New Semester
Started
Get
50% OFF
Study Help!
--h --m --s
Claim Now
Question Answers
Textbooks
Find textbooks, questions and answers
Oops, something went wrong!
Change your search query and then try again
S
Books
FREE
Study Help
Expert Questions
Accounting
General Management
Mathematics
Finance
Organizational Behaviour
Law
Physics
Operating System
Management Leadership
Sociology
Programming
Marketing
Database
Computer Network
Economics
Textbooks Solutions
Accounting
Managerial Accounting
Management Leadership
Cost Accounting
Statistics
Business Law
Corporate Finance
Finance
Economics
Auditing
Tutors
Online Tutors
Find a Tutor
Hire a Tutor
Become a Tutor
AI Tutor
AI Study Planner
NEW
Sell Books
Search
Search
Sign In
Register
study help
business
elementary statistics
Just The Essentials Of Elementary Statistics 10th Edition Robert Johnson, Patricia Kuby - Solutions
a. Find the z-score for the 33rd percentile of the standard normal distribution.b. Find the z-scores that bound the middle 40% of the standard normal distribution.
Assuming a normal distribution, find the z-score associated with the following:a. The 90th percentileb. The 95th percentilec. The 99th percentile
Assuming a normal distribution, what is the z-score associated with the following:a. 1st quartileb. 2nd quartilec. 3rd quartile
Skillbuilder Applet Exercise demonstrates that probability is equal to the area under a curve. Given that college students sleep an average of 7 hours per night with a standard deviation equal to 1.7 hours, use the scroll bar in the applet to find the following:a. P(a student sleeps between 5 and 9
Given x 58, 43, and 5.2, find z.
Given x 237, 220, and 12.3, find z.
Given that x is a normally distributed random variable with a mean of 28 and a standard deviation of 7, find the following probabilities:a. P (x 28)b. P (28 x 38)c. P (24 x 40)d. P (30 x 45)e. P (19 x 35)f. P (x 48)
Using the information given in Example 6.10(p. 324):a. Find the probability that a randomly selected person will have an IQ score between 100 and 120.b. Find the probability that a randomly selected person will have an IQ score above 80.
Using the information given in Example 6.14 on page 326:a. Find the probability that a randomly selected junior executive has a salary between $27,000 and $31,000.b. Find the probability that a randomly selected junior executive has a salary greater than$33,000.
Depending on where you live and on the quality of the day care, costs of day care can range from $3000 to $15,000 a year (or $250 to $1250 monthly) for one child, according to the Baby Center.Day-care centers in large cities such as New York and San Francisco are notoriously expensive.Source:
According to Wageweb.com (http://www.wageweb.com/hr1.htm), the national average salary as of October 2003 for a human resources clerk was $29,932. If we assume that the annual salaries for clerks are normally distributed with a standard deviation of $1850, find the following:a. The percentage who
According to the Federal Highway Administration’s 2003 highway statistics (http://www.fhwa.dot.gov), the distribution of ages for licensed drivers has a mean of 44.5 years and a standard deviation of 17.1 years. Assuming the distribution of ages is normally distributed, what percentage of the
There is a new working class with money to burn according to the USA Today article titled “New‘gold-collar’ young workers gain clout” (March 1, 2005). “Gold-collar” is a subset of blue-collar workers defined by researchers as those working in fast-food and retail jobs or as security
The International Bottled Water Association says that Americans on the average drink 4.6 (8-oz.)servings of water a day (http://www.bottledwater.org/public/summary.htm). Assuming that the number of 8-oz. servings of water is approximately normally distributed with a standard deviation of 1.4
According to the American College Test(ACT), results from the 2004 ACT testing found that students had a mean reading score of 21.3 with a standard deviation of 6.0. Assuming that the scores are normally distributed:a. Find the probability that a randomly selected student has a reading ACT score
The diameter of each cork, as described in Applied Example 6.15, is measured in several places, and an average diameter is reported for the cork. The average diameter has a normal distribution with a mean of 24.0 mm and standard deviation of 0.13 mm.a. The specs for this variable, given in Applied
Using the standard normal curve and z:a. Find the minimum score needed to receive an A if the instructor in Example 6.12 (p. 325)said the top 15% were to get As.b. Find the 25th percentile for IQ scores in Example 6.10 (p. 324).c. If 20% of the salaries in Example 6.14 (p. 326)are below $28,000,
“On hold” times for callers to a local cable television company are known to be normally distributed with a standard deviation of 1.3 minutes.Find the average caller “on hold” time if the company maintains that no more than 10% of callers wait more than 6 minutes.
[EX06-063] The data are the net weights (in grams) for a sample of 30 bags of M&M’s. The advertised net weight is 47.9 grams per bag.46.22 46.72 46.94 47.61 47.67 47.70 47.98 48.28 48.33 48.45 48.49 48.72 48.74 48.95 48.98 49.16 49.40 49.69 49.79 49.80 49.80 50.01 50.23 50.40 50.43 50.97 51.53
a. Generate a random sample of 100 simulated values from a normal distribution with a mean of 50 and a standard deviation of 12.b. Using the random sample of 100 simulated values found in part a and the technology commands for calculating ordinate values on page 328, find the 100 corresponding y
Use a computer or calculator to find the probability that one randomly selected value of x from a normal distribution (mean of 584.2 and standard deviation of 37.3) will have a value that corresponds to the following:a. Less than 525b. Between 525 and 590c. At least 590d. Verify the results of
a. Use a computer to generate your own abbreviated standard normal probability table (a short version of Table 3). Use z-values of 0.0 to 5.0 in intervals of 0.1.b. How are the values obtained related to Table 3 entries? Make the necessary adjustment and store the results in a column.c. Compare
Use a computer to compare a random sample to the population from which the sample was drawn. Consider the normal population with mean 100 and standard deviation 16.a. List values of x from 4 to 4 in increments of half standard deviations and store them in a column.b. Find the ordinate (y
Use a computer to compare a random sample to the population from which the sample was drawn. Consider the normal population with mean 75 and standard deviation 14. Answer questions a–f of Exercise 6.67 using N(75, 14).
Suppose you were to generate several random samples, all the same size, all from the same normal probability distribution. Will they all be the same? How will they differ? By how much will they differ?a. Use a computer or calculator to generate 10 different samples, all of size 100, all from the
Generate 10 random samples, each of size 25, from a normal distribution with mean 75 and standard deviation 14. Answer questions parts b–d of Exercise 6.69.
Find the value of the following:a. z(0.15)b. z(0.82)
Find the value of the following:a. z(0.08)b. z(0.92)
Use Table 3 in Appendix B to find the following values of z.a. z(0.05)b. z(0.01)c. z(0.025)d. z(0.975)e. z(0.98)
Complete the following charts of z-scores.The area A given in the tables is the area to the right under the normal distribution in the figures.a. z-scores associated with the right-hand tail:Given the area A, find z(A).b. z-scores associated with the left-hand tail:Given the area B, find z(B). Z(A)
The z notation, z(), combines two related concepts—the z-score and the area to the right—into a mathematical symbol. Identify the letter in each of the following as being a z-score or being an area; then, with the aid of a diagram, explain what both the given number and the letter represent on
Understanding the z notation, z(), requires us to know whether we have a z-score or an area.Each of the following expressions use the z notation in a variety of ways, some typical and some not so typical. Find the value asked for in each of the following; then, with the aid of a diagram, explain
In which of the following binomial distributions does the normal distribution provide a reasonable approximation? Use computer commands to generate a graph of the distribution and compare the results to the “rule of thumb.” State your conclusions.a. n 10, p 0.3b. n 100, p 0.005c. n
Find the normal approximation for the binomial probability P(x 6), where n 12 and p 0.6. Compare this to the value of P(x 6) obtained from Table 2 in Appendix B.
Find the normal approximation for the binomial probability P(x 4, 5), where n 14 and p 0.5. Compare this to the value of P(x 4, 5)obtained from Table 2 in Appendix B.
Find the normal approximation for the binomial probability P(x 8), where n 14 and p 0.4. Compare this to the value of P(x 8) obtained from Table 2 in Appendix B.
Find the normal approximation for the binomial probability P(x 9), where n 13 and p 0.7. Compare this to the value of P(x 9) obtained from Table 2 in Appendix B.
Referring to Example 6.19 (p. 346):a. Calculate P(x 3 B(25, 1 3)). (Hint: If you use a computer or calculator, use the commands on p. 292.)b. How good was the normal approximation? Explain.
Melanoma is the most serious form of skin cancer and is increasing at a rate higher than any other cancer in the United States. If it is caught in its early stage, the survival rate for patients is almost 90% in the United States. What is the probability that 200 or more of some group of 250
If 30% of all students entering a certain university drop out during or at the end of their first year, what is the probability that more than 600 of this year’s entering class of 1800 will drop out during or at the end of their first year?6.95 According to the Federal Highway Administration,
According to a February 2005 survey completed by the Pew Internet & American Life Project, about 36 million Americans, or 27% of Internet users, say they download either music or video files. Assuming the percentage is correct, use the normal approximation to the binomial to find the probability of
Not all NBA coaches who enjoyed lengthy careers were consistently putting together winning seasons with the teams they coached. For example, Bill Fitch, who coached for 25 seasons of professional basketball after starting his coaching career at the University of Minnesota, won 944 games but lost
One poll found that more than 6 in 10 voters say they believe the United States is ready for a female president. The poll was conducted in February 2005 by the Siena College Research Institute and was sponsored by Hearst Newspapers. Assuming that the proportion is 0.6, what is the probability that
According to an April 2005 report from the Substance Abuse and Mental Health Services Administration(SAMHSA), 35% of people involved in treatment began drinking heavily between ages 15 and 17 (http://www.jointogether.org). Use the normal approximation to the binomial distribution to find the
In 2003, of the nearly 105 million native wage and salary workers in the United States, approximately 15.4 million were affiliated with a union. Use the normal approximation to the binomial distribution to find the probability that in a national survey of 2500 workers, at most 400 will be union
Find the area under the normal curve that lies between the following pairs of z-values:a. z3.00 and z 3.00b. z(0.975) and z(0.025)c. z(0.10) and z(0.01)
The 70-year long-term record for weather shows that for New York State, the annual precipitation has a mean of 39.67 inches and a standard deviation of 4.38 inches.Source: Department of Commerce; State, Regional and National Monthly Precipitation Report If the annual precipitation amount has a
American Express charges merchants higher fees than any other credit or debit card, according to the USA Today article “American Express fees take flak” (December 23, 2004). The company believes they can do this because they claim the customers using the American Express card spend more. The
A company that produces rivets used by commercial aircraft manufacturers knows that the shearing strength (force required to break) of its rivets is of major concern. The company believes the shearing strength of its rivets is normally distributed with a mean of 925 pounds and a standard deviation
In a study of the length of time it takes to play major league baseball games during the early 2005 season, the variable “time of game” appears to be normally distributed with a mean of 2 hours, 50.1 minutes and a standard deviation of 20.99 minutes.Source: MLB.coma. Some fans describe a game
A certain type of refrigerator has a length of life that is approximately normally distributed with a mean of 4.8 years and a standard deviation of 1.3 years.a. If this machine is guaranteed for 2 years, what is the probability that the machine you purchased will require replacement under the
A machine is programmed to fill 10-oz. containers with a cleanser. However, the variability inherent in any machine causes the actual amounts of fill to vary. The distribution is normal with a standard deviation of 0.02 oz. What must the mean amount be in order that only 5% of the containers
A soft-drink vending machine can be regulated to ensure that it dispenses an average of oz.of soft drink per glass.a. If the ounces dispensed per glass are normally distributed with a standard deviation of 0.2 oz., find the setting for that will allow a 6-oz.glass to hold (without overflowing)
a. Use a computer or calculator to list the binomial probabilities for the distribution where n 50 and p 0.1.b. Use the results from part a and find P(x 6).c. Find the normal approximation for P(x 6), and compare the results with those in part b.
a. Use a computer or calculator to list both the probability distribution and the cumulative probability distribution for the binomial probability experiment with n 40 and p 0.4.b. Explain the relationship between the two distributions found in part a.c. If you could use only one of these lists
A test-scoring machine is known to record an incorrect grade on 5% of the exams it grades.Use the appropriate method to find the probability that the machine records the following:a. Exactly 3 wrong grades in a set of 5 examsb. No more than 3 wrong grades in a set of 5 examsc. No more than 3 wrong
A company asserts that 80% of the customers who purchase its special lawn mower will require no repairs during the first 2 years of ownership.Your personal study has shown that only 70 of the 100 in your sample lasted the 2 years without incurring repair expenses. What is the probability of your
In a February 2005 poll conducted by Salary.com, firefighters hosed down the competition and won the title of “sexiest job,” with 16% of the votes. Suppose you randomly selected 50 adults. Use the normal approximation to the binomial distribution to find the probability that from within your
The 2004 Pew Internet & American Life Project survey revealed that 4 in 10 online Americans—about 53 millions American adults—use instant messaging (IM) software.Source: http://www.pewinternet.org/PPF/r/133/report_ display.asp Use the normal approximation to the binomial to find the probability
The National Coffee Drinking Trends is “the publication” in the coffee industry. For more than five decades, it has tracked annual consumption patterns in a wide variety of situations and categories.The 2004 edition says that 39% of the total coffee drinkers 18 years and older purchased
Apparently, playing video games, watching TV, and instant messaging friends isn’t relaxing enough. In a February 2005 poll from Yesawich, Pepperdine, Brown and Russell found that onethird of the children polled said they helped research some aspect of their family’s vacation on the Internet. If
The U.S. civilian labor force of 148,157,000 workers was 94.8% employed in March 2005. If a random sample of 2500 is taken from the civilian labor force, what is the probability of the following:a. More than 6% of the sample will be unemployed.b. Less than 5% of the sample will be unemployed.
During the first 2 months of 2005, there were 1,140,256 commercial airline flights in and out of U.S. airports. Of these, 74.35% were ontime arrivals and 18.96% were late departures.Three hundred flights are to be randomly identified from all flights and their flight logs examined closely. What is
Infant mortality rates are often used to assess quality of life and adequacy of health care. The rate is based on the number of deaths of infants younger than 1 year old in a given year per 1000 live births in the same year. Listed here are the infant mortality rates, to the nearest integer, for
[EX06-134] A large sample was randomly selected from a competitive product and evaluated for a particular lens dimension. It was then compared with its specification range of Nominal(0.000) 0.030 unit. A total of 110 lenses were evaluated. The data were coded in two ways and shown here:0.020
Assume the distribution of data in Exercise 6.134 was exactly normally distributed with a mean of 0.00 and standard deviation of 0.020.a. Find the bounds of the middle 95% of the distribution?b. What percent of the data actually is within the interval found in part a?c. Using z-scores, determine
The following triangular distribution provides an approximation to the normal distribution.Line segment l1 has the equation y x/9 1/3, and segment l2 has the equation yx/9 1/3.a. Find the area under the entire triangular distribution.b. Find the area under the triangular distribution between 0
Let’s take a second look at the normally distributed IQ scores illustrated in Section 6.1, “Intelligence Scores” (p. 313). If completed, use your Exercise 6.1 solutions as a basis.a. How is an IQ score converted to a standard score?b. What is the standard score for an IQ score of 90? 110?
Intelligence Testsa. Use the information in Table 10-4 on page 356 and estimate the standard deviation for adult WAIS-R scores. Use at least two different pieces of information to obtain two separate estimates.Determine your answer.b. Does the IQ score discussed here seem to have a normal
Find the following probabilities for z, the standard normal score:a. P (0 z 2.42)b. P (z 1.38)c. P (z1.27)d. P (1.35z2.72)6.12 Find the value of each z-score:a. P(z ?) 0.2643b. P(z ?) 0.17c. z(0.04)
Use the symbolic notation z() to give the symbolic name for each z-score shown in the figure at the bottom of the page.
The lifetimes of flashlight batteries are normally distributed about a mean of 35.6 hr with a standard deviation of 5.4 hr. Kevin selected one of these batteries at random and tested it. What is the probability that this one battery will last less than 40.0 hr?
The lengths of time, x, spent commuting daily, one-way, to college by students are believed to have a mean of 22 min with a standard deviation of 9 min. If the lengths of time spent commuting are approximately normally distributed, find the time, x, that separates the 25% who spend the most time
Thousands of high school students take the SAT each year. The scores attained by the students in a certain city are approximately normally distributed with a mean of 490 and a standard deviation of 70. Find:a. the percentage of students who score between 600 and 700b. the percentage of students who
In 50 words, describe the standard normal distribution.
Describe the meaning of the symbol z().
Explain why the standard normal distribution, as computed in Table 3 in Appendix B, can be used to find probabilities for all normal distributions.
a. How would you graphically describe the 100 “ages” in the preceding random sample taken from the 2000 census distribution?Construct the graph.b. Using the graph that you constructed in parta, describe the shape of the distribution of sample data.c. How well did the sample describe the
a. How would you numerically describe the 100 “ages” in the preceding random sample taken from the 2000 census distribution?Calculate the statistics.b. How well do the statistics calculated in part a compare with the parameters from the 2000 census? Be specific.c. If another sample was
Manufacturers use random samples to test whether or not their product is meeting specifications.These samples could be people, manufactured parts, or even samples during the manufacturing of potato chips.a. Do you think that all random samples taken from the same population will lead to the same
Refer to Table 7.1 in Example 7.1 (p. 363) and explain why the samples are equally likely; that is, why P(0) 0.04, and why P(2) 0.12.
Consider the set of even single-digit integers{0, 2, 4, 6, 8}.a. Make a list of all the possible samples of size 3 that can be drawn from this set of integers.(Sample with replacement; that is, the first number is drawn, observed, and then replaced[returned to the sample set] before the next
Using the telephone numbers listed in your local directory as your population, randomly obtain 20 samples of size 3. From each telephone number identified as a source, take the fourth, fifth, and sixth digits. (For example, for 245-8269, you would take the 8, the 2, and the 6 as your sample of size
Using a set of five dice, roll the dice and determine the mean number of dots showing on the five dice. Repeat the experiment until you have 25 sample means.a. Draw a dotplot showing the distribution of the 25 sample means. (See Example 7.2, p. 364.)b. Describe the distribution of x’s in part
Considering the population of five equally likely integers in Example 7.2:a. Verify and for the population in Example 7.2.b. Table 7.3 lists 30 x values. Construct a grouped frequency distribution to verify the frequency distribution shown in Figure 7.4.c. Find the mean and standard deviation
a. Using a computer or a random-numbers table, simulate the drawing of 100 samples, each of size 5, from the uniform probability distribution of single-digit integers, 0 to 9.b. Find the mean for each sample.c. Construct a histogram of the sample means.(Use integer values as class midpoints.)d.
Skillbuilder Applet Exercise simulates taking samples of size 4 from an approximately normal population, where 65.15 and 2.754.a. Click “1” for “# Samples.” Note the four data values and their mean. Change “slow” to “batch” and take at least 1000 samples using the “500” for
Skillbuilder Applet Exercise simulates sampling from a skewed population, where 6.029 and 10.79.a. Change the “# Observations per sample”to “4.” Using batch and 500, take 1000 samples of size 4.b. Compare the mean and standard deviation for the sample means with and . Compare the
An April 2004 article on HearTheIssues.comstated that Americans have an average of 2.24 televisions per household (source: Nielsen Media Research).If the standard deviation for the number of televisions in a U.S. household is 1.2 and a random sample of 80 American households is selected, the mean
An April 2004 article on HearTheIssues.comstated that Americans watch an average of 4.0 hours of television per person per day (source:Nielsen Media Research). If the standard deviation for the number of hours of television watched per day is 2.1 and a random sample of 250 Americans is selected,
According to The World Factbook, 2004, the total fertility rate (estimated mean number of children born per woman) for Madagascar is 5.7. Suppose that the standard deviation of the total fertility rate is 2.6. The mean number of children for a sample of 200 randomly selected women is one value of
The USDA Economics and Statistics System at Cornell University maintains a Poultry Yearbook in which they list monthly, quarterly, and annual facts about the poultry industry. The 2004 yearbook lists the annual consumption of turkey meat as 17.71 pounds per person. Suppose the standard deviation
a. Use a computer to randomly select 100 samples of size 6 from a normal population with mean 20 and standard deviation 4.5.b. Find mean x for each of the 100 samples.c. Using the 100 sample means, construct a histogram, find mean x, and find the standard deviation sx.d. Compare the results of
a. Use a computer to randomly select 200 samples of size 24 from a normal population with mean 20 and standard deviation 4.5.b. Find mean x for each of the 200 samples.c. Using the 200 sample means, construct a histogram, find mean x , and find the standard deviation sx.d. Compare the
Consider a normal population with 43 and 5.2. Calculate the z-score for an x of 46.5 from a sample of size 16.
Consider a population with 43 and 5.2.a. Calculate the z-score for an x of 46.5 from a sample of size 35.b. Could this z-score be used in calculating probabilities using Table 3 in Appendix B? Why or why not?
In Example 7.5, explain how 0.4772 was obtained and what it is.
The local bakery bakes more than a thousand 1-pound loaves of bread daily, and the weights of these loaves varies. The mean weight is 1 lb. and 1 oz., or 482 grams. Assume the standard deviation of the weights is 18 grams and a sample of 40 loaves is to be randomly selected.a. This sample of 40 has
Consider the approximately normal population of heights of male college students with mean 69 inches and standard deviation 4 inches. A random sample of 16 heights is obtained.a. Describe the distribution of x, height of male college students.b. Find the proportion of male college students
The amount of fill (weight of contents) put into a glass jar of spaghetti sauce is normally distributed with mean 850 grams and standard deviation 8 grams.a. Describe the distribution of x, the amount of fill per jar.b. Find the probability that one jar selected at random contains between
Showing 1700 - 1800
of 7930
First
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
Last
Step by Step Answers
Get 50% OFF
Claim Now
