Questions and Answers of Essentials Of Statistics

Exercise 12 “Diet Coke”Data From Exercise 12The weights (lb) of the contents in cans of Diet Coke, as listed in Data Set 26 “Cola Weights and Volumes” in Appendix B.In use the Excel, or
Assume that cans of Coke are filled so that the actual amounts are normally distributed with a mean of 12.00 oz and a standard deviation of 0.11 oz.a. Find the probability that a single can of Coke
When Mendel conducted his famous genetics experiments with peas, one sample of offspring consisted of 929 peas, with 705 of them having red flowers. If we assume, as Mendel did, that under these
Less than -1.23In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case, draw a
Less than –1.96In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case, draw
The Ethan Allen tour boat capsized and sank in Lake George, New York, and 20 of the 47 passengers drowned. Based on a 1960 assumption of a mean weight of 140 lb for passengers, the boat was rated to
The following are the values of net worth (in thousands of dollars) of recent members of the executive branch of the U.S. government. Test these values for normality, then take the logarithm of
Less than 1.28In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case, draw a
A sample of human brain volumes (cm3) is obtained from those listed in Data Set 8 “IQ and Brain Size” in Appendix B: 1027, 1029, 1034, 1070, 1079, 1079, 963, 1439.In use the given data values to
Less than 2.56In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case, draw a
When she was 9 years of age, Emily Rosa did a science fair experiment in which she tested professional touch therapists to see if they could sense her energy field. She flipped a coin to select
Greater than 0.25In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case, draw
The U.S. Air Force requires that pilots have heights between 64 in. and 77 in.a. Find the percentage of men meeting the height requirement.b. If the Air Force height requirements are changed to
Greater than 0.18In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case, draw
Greater than –2.00In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case,
In a survey of 1002 people, 70% said that they voted in a recent presidential election (based on data from ICR Research Group). Voting records show that 61% of eligible voters actually did vote.a.
The Gulfstream 100 is an executive jet that seats six, and it has a doorway height of 51.6 in.a. What percentage of adult men can fit through the door without bending?b. Does the door design with a
Greater than –3.05In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case,
In a study of facial behavior, people in a control group are timed for eye contact in a 5-minute period. Their times are normally distributed with a mean of 184.0 seconds and a standard deviation of
Between 2.00 and 3.00In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case,
Between 1.50 and 2.50In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case,
Between and – 2.55 and – 2.00In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In
Between – 2.75 and – 0.75In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In
Between -2.00 and 2.00In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case,
Between -3.00 and 3.00In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case,
Find the sample size needed to estimate the percentage of California residents who are left-handed. Use a margin of error of three percentage points, and use a confidence level of 99%.a. Assume that
Between –1.00 and 5.00In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each
Between – 4.27 and 2.34In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each
Less than 4.55Between – 4.27 and 2.34In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of
Greater than – 3.75In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case,
In order to better plan for student resources, the chairperson of the mathematics department at Broward College wants to estimate the percentage of students who own a computer. If we want to estimate
Greater than 0In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case, draw a
A professor gives a test and the scores are normally distributed with a mean of 60 and a standard deviation of 12. She plans to curve the scores.a. If she curves by adding 15 to each grade, what is
Less than 0In assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. In each case, draw a
Data Set 21 “Earthquakes” in Appendix B includes the depths (km) of the sources of 600 earthquakes. Use technology for the following.a. Find the mean and standard deviation of the 600 depths.b.
1. Use the survey results to construct a 95% confidence a interval estimate of the percentage of all adults who know what Twitter is.2. Identify the margin of error for this survey.3. Explain why it
Why does the bootstrap method require sampling with replacement? What would happen if we used the methods of this section but sampled without replacement?
Repeat Exercise 7 “Freshman 15” using a confidence level of 90% for parts (a) And (b) And using 1000 bootstrap samples instead of the 10 that were given in Exercise 7.Data From Exercise
A clinical trial was conducted to test the effectiveness of the drug zopiclone for treating insomnia in older subjects. After treatment with zopiclone, 16 subjects had a mean wake time of 98.9 min
You want to estimate σ for the population of waiting times for the Space Mountain ride in Walt Disney World. You want to be 99% confident that the sample standard deviation is within 1% of σ. Find
When setting specifications of quarters to be accepted in a vending machine, you must estimate the standard deviation of the population of quarters in use. Find the minimum sample size needed to be
Data Set 1 “Body Data” in Appendix B includes weights of 153 randomly selected adult males, and those weights have a standard deviation of 17.65 kg. Because it is reasonable to assume that
In use these results from a USA Today survey in which 510 people chose to respond to this question that was posted on the USA Today website: “Should Americans replace passwords with biometric
Consider the probability distribution defined by the formula where x can be any value between 0 and 10 inclusive (not just integers).The accompanying graph of this probability distribution shows that
The largest health experiment ever conducted involved a test of the Salk vaccine designed to protect children from the devastating effects of polio. The test included 201,229 children who were given
Data Set 26 “Cola Weights and Volumes” in Appendix B includes volumes (oz) of regular Coke. Based on that data set, assume that the cans are produced so that the volumes have a standard deviation
If we are using the sample data from Exercise 1 for a t test of the claim that the population mean is greater than 90 sec, what does df denote, and what is its value?Data From Exercise 1Twelve
Determine whether the given claim involves a hypothesis test that is left-tailed, twotailed, or right-tailed.a. p ≠ 0.5b. μ < 98.6°Fc. σ > 15 cm
If we use the same significance level to conduct the hypothesis test using the P-value method, the critical value method, and a confidence interval, which method is not equivalent to the other two?In
Find the P-value in a test of the claim that the mean annual income of a CIA agent is greater than $81,623 (based on data from payscale.com) given that the test statistic is t = 1.304 for a sample of
In identify the indicated values or interpret the given display. Use the normal distribution as an approximation to the binomial distribution, as described in Part 1 of this section. Use a 0.05
In do the following:a. Express the original claim in symbolic form.b. Identify the null and alternative hypotheses.
The claim is that for Verizon data speeds at airports, the mean is μ = 14.00 mbps. The sample size is μ = 13 and the test statistic is t = –1.625In either use technology to find the P-value or
True or false: In hypothesis testing, it is never valid to form a conclusion of supporting the null hypothesis.
True or false: The conclusion of “fail to reject the null hypothesis” has exactly the same meaning as “accept the null hypothesis.”
Repeat the preceding exercise using the pulse rates of women listed in Data Set 1 “Body Data” in Appendix B. For the sample of pulse rates of women, n = 147 and s = 12.5. See the accompanying JMP
True or false: If correct methods of hypothesis testing are used with a large simple random sample that satisfies the test requirements, the conclusion will always be true.
In a test of the claim that σ = 15 for the population of IQ scores of professional athletes, we find that the rightmost critical value is χ2R = 40.646. Is the leftmost critical χ2L value
Explain what is meant by the statements that the t test for a claim about μ is robust, but the χ2 test for a claim about σ2 is not robust.
Which of the following statements are true?a. When testing a claim about a population mean m, the P-value method, critical value method, and confidence interval method are all equivalent in the sense
Exercise 6 “Cell Phone”Data From Exercise 6Claim: Fewer than 95% of adults have a cell phone. In a Marist poll of 1128 adults, 87% said that they have a cell phone.In refer to the exercise
The proportion of adults who use the Internet is greater than 0.87.In provide statements that identify the type I error and the type II error that correspond to the given claim. (Although conclusions
The proportion of people who require no vision correction is less than 0.25.In provide statements that identify the type I error and the type II error that correspond to the given claim. (Although
Among 460 overtime National Football League (NFL) games between 1974 and 2011, 252 of the teams that won the overtime coin toss went on to win the game. During those years, a team could win the coin
a. Assume that we want to use a 0.05 significance level to test the claim that p1 < p2. Which is better: A hypothesis test or a confidence interval?b. In general, when dealing with inferences for
The New York Times published an article about a study in which Professor Denise Korniewicz and other Johns Hopkins researchers subjected laboratory gloves to stress. Among 240 vinyl gloves, 63%
Carpal tunnel syndrome is a common wrist complaint resulting from a compressed nerve, and it is often the result of extended use of repetitive wrist movements, such as those associated with the use
If we use the sample data in Exercise 2 for constructing a 99% confidence interval, what is the number of degrees of freedom that should be used for finding the critical value of tα/2? What is the
a. Exercise 2 includes a confidence interval. If you use the P-value method or the critical value method from Part 1 of this section to test the claim that women and men have the same mean hemoglobin
When testing the claim that p1 = p2, a test statistic of z = -1.64 is obtained. Find the P-value for the hypothesis test.In use the following survey results: Randomly selected subjects were asked if
Construct a scatterplot of the father/son heights, then interpret it.In use the following heights (in.) The data are matched so that each column consists of heights from the same family.
1. Out-of-class activity The Chapter Problem is based on observations of cars with rear license plates only in states with laws that require both front and rear license plates. Work together in
Use the same data from Exercise 6 and use the same scale to construct a boxplot of the braking reaction times of males and another boxplot for the braking reaction times of females. What do the
Use the sample data from Exercise 6 with a 0.01 significance level to test the claim that males and females have the same mean.Data from in Exercise 6Listed below are sorted braking reaction times
Since the Hawk-Eye instant replay system for tennis was introduced at the U.S. Open in 2006, men challenged 2441 referee calls, with the result that 1027 of the calls were overturned. Women
Repeat Exercise 8 “The Spoken Word” using all of the data in the first two columns of Data Set 24 “Word Counts” in Appendix B.Data From Exercise 8Listed below are the numbers of words spoken
What is the difference between the regression equation ŷ = b0 + b1x and the regression equation y = β0 + β1x?
Use only the sunspot numbers for the following.a. Find the mean, median, range, standard deviation, and variance.b. Are the sunspot numbers categorical data or quantitative data?c. What is the level
In a trial designed to test the effectiveness of aspirin in preventing heart disease, 11,037 male physicians were treated with aspirin and 11,034 male physicians were given placebos. Among the
Repeat Exercise 14 using all of the paired duration>interval after times listed in Data Set 23.Data From Exercise 14Using the listed duration and interval after times, find the best predicted
The efficiency of the rank correlation test is 0.91, which indicates that with all other factors being the same, rank correlation requires 100 pairs of sample observations to achieve the same results
Table A-5 lists critical values of r for selected values of n and a. Table A-5More generally, critical r values can be found by using the formula where the t value is found from the table
Use the frequency distribution from Exercise 11 in Section 2-1 on page 49 to construct a histogram. Does it appear to be the graph of data from a population with a normal distribution?In construct
Construct a stemplot of the body temperatures listed in Exercise 1. Are there any outliers?Data From Exercise 1Construct a frequency distribution of the 20 body temperatures (oF) listed below. (These
Use the frequency distribution from Exercise 12 in Section 2-1 on page 49 to construct a histogram. Does the histogram appear to be skewed? If so, identify the type of skewness.In construct the
During the last presidential election, CNN conducted an exit poll in which specific polling stations were randomly selected and all voters were surveyed as they left the premises.In identify which of
Blood lead levels of low, medium, and high used to describe the subjects in Data Set 7 “IQ and Lead” in Appendix BIn determine which of the four levels of measurement (nominal, ordinal, interval,
Refer to the frequency distribution from Exercise 5.Data From Exercise 5In Exercises 9 and 10, using a loose interpretation of the criteria for determining whether a frequency distribution is
In an investigation of a relationship between systolic blood pressure and diastolic blood pressure of adult females, which of the following graphs is most helpful: histogram; pie chart; scatterplot;
Refer to the frequency distribution from Exercise 6.Data From Exercise 6In Exercises 9 and 10, using a loose interpretation of the criteria for determining whether a frequency distribution is
In Florida’s Play 4 lottery game, four digits between 0 and 9 inclusive are randomly selected each day. We normally expect that each of the 10 different digits will occur about 1/10 of the time,
Use the frequency distribution from Exercise 17 in Section 2-1 on page 49 to construct a histogram. What can be concluded from the distribution of the digits? Specifically, do the heights appear to
Use the frequency distribution from Exercise 11 in Section 2-1 on page 49 to construct a frequency polygon. Does the graph suggest that the distribution is skewed? If so, how?In construct the
Use the frequency distribution from Exercise 13 in Section 2-1 on page 49 to construct a histogram. Does the histogram appear to be skewed? If so, identify the type of skewness.In construct the
Use the frequency distribution from Exercise 14 in Section 2-1 on page 49 to construct a histogram. Using a strict interpretation of the criteria for being a normal distribution, does the histogram
Use the frequency distribution from Exercise 12 in Section 2-1 on page 49 to construct a frequency polygon. Does the graph suggest that the distribution is skewed? If so, how?In construct the
Use the frequency distribution from Exercise 15 in Section 2-1 on page 49 to construct a histogram. Does the histogram appear to be skewed? If so, identify the type of skewness.In construct the
Use the frequency distribution from Exercise 16 in Section 2-1 on page 49 to construct a histogram. In using a strict interpretation of the criteria for being a normal distribution, does the
Use the frequency distribution from Exercise 18 in Section 2-1 on page 49 to construct a histogram. What can be concluded from the distribution of the digits? Specifically, do the heights appear to
Refer to Data Set 24 “Word Counts” in Appendix B, which includes counts of words spoken by males and females. That data set includes 12 columns of data, but first stack all of the male word

Showing 400 - 500 of 531