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The number of wireless devices in each U.S. household. Determine whether the data set is a population or a sample. Explain your reasoning. Use the Venn diagram to identify the population and the sample. Incomes of Home Owners in Massachusetts Incomes of home owners in Massachusetts with mortgages Incomes of home owners in Massachusetts... A survey of 159 U.S. law firms found that the average hourly billing rate for partners was $604. Identify the population and the sample. Describe the sample data set. A students score on the Fundamentals of Engineering exam is in the 89th percentile. Make an observation about the students exam score. A random number generator is used to select a number from 1 to 100. What is the probability of selecting the number 153? Match the event with its probability. (a) 0.95 (b) 0.005 (c) 0.25 (d) 0 (e)... A game show contestant must randomly select a door. One door doubles her money while the other three doors leave her with no winnings. What is the probability she selects the door that doubles her... The probability that an event will not happen is given. Find the probability that the event will happen. P(E') = 21/61 Guessing the initial of a students middle name. Identify the sample space of the probability experiment and determine the number of outcomes in the sample space. Draw a tree diagram then appropriate. Give three observations that can be made from the graph. Monthly Active Users on 5 Social Networking Sites as of September 2016 1750 1500 1250 1000 750 500 250 Site Number of users (in millions)... The mean is the measure of central tendency most likely to be affected by an outlier. Determine whether the statement is true or false. If it is false, rewrite it as a true statement. Determine whether the approximate shape of the distribution in the histogram is symmetric, uniform, skewed left, skewed right, or none of these. Justify your answer. 18 15 12 9- 2 3 4 5 6 7 8 9 10 11... Find the mean, the median, and the mode of the data, if possible. If any measure cannot be found or does not represent the center of the data, explain why. Weights (in pounds) of Packages on a... You are applying for jobs at two companies. Company A offers starting salaries with = $41,000 and = $1000. Company B offers starting salaries with = $41,000 and = $5000. From which company are... Construct a cumulative frequency distribution and an ogive for the data set using six classes. Then describe the location of the greatest increase in frequency. Retirement Ages Data set: Retirement... Event A: Randomly select a member of the U.S. Congress. Event B: Randomly select a male U.S. Senator. Determine whether the events are mutually exclusive. Explain your reasoning. Use the ogive to approximate (a) the number in the sample. (b) the location of the greatest increase in frequency. Black Bears 80 Weight (in pounds) Cumulative frequency 72.5 115.5 158.5 201.5 244.5... The table shows the results of a survey that asked 506 Maine adults whether they favored or opposed a tax to fund education. A person is selected at random from the sample. Find the probability of... The state of Virginias license plates have three letters and four digits. Assuming that any letter or digit can be used, how many different license plates are possible? Use the Fundamental Counting... The probability of rolling 2 six-sided dice and getting a sum of 9 is 1/9. Classify the statement as an example of classical probability, empirical probability, or subjective probability. Explain... Determine whether the events are mutually exclusive. Explain your reasoning. Event A: Randomly select a student born on the 30th of a month Event B: Randomly select a student with a birthday in... (a) Find the mean, variance, and standard deviation of the probability distribution, and (b) Interpret the results. The number of games played in each World Series from 1903 through 2016 6. 8 Games... Sixty-two percent of U.S. adults get news on social media sites. You randomly select five U.S. adults. Find the probability that the number of U.S. adults who get news on social media sites is (a)... A restaurant offers a $15 dinner special that lets you choose from 6 appetizers, 12 entres, and 8 desserts. How many different meals are available when you select an appetizer, an entre, and a... Thirty-six percent of Americans think there is still a need for the practice of changing their clocks for Daylight Savings Time. You randomly select seven Americans. Find the probability that the... Assuming that no questions are left unanswered, in how many ways can a six-question true or false quiz be answered? Use the Fundamental Counting Principle. Use the bar graph at below, which shows the highest level of education received by employees of a company. Find the probability that the highest level of education for an employee chosen at random is... Find each probability. (a) P(x > 20) (b) P(0 < x < 5) (c) P(x < 9 or x > 27) The random variable x is normally distributed with mean = 18 and standard deviation = 7.6. Random samples of size 8 are drawn from the population and the mean of each sample is determined. Is the sampling distribution of sample means normally distributed? Explain. The per capita disposable... For the same sample statistics, which level of confidence would produce the widest confidence interval? Explain your reasoning. (a) 90% (b) 95% (c) 98% (d) 99% Determine whether the graph could represent a variable with a normal distribution. Explain your reasoning. If the graph appears to represent a normal distribution, estimate the mean and standard... Determine whether the graph could represent a variable with a normal distribution. Explain your reasoning. If the graph appears to represent a normal distribution, estimate the mean and standard... Determine whether the graph could represent a variable with a normal distribution. Explain your reasoning. If the graph appears to represent a normal distribution, estimate the mean and standard... Determine whether the graph could represent a variable with a normal distribution. Explain your reasoning. If the graph appears to represent a normal distribution, estimate the mean and standard... Find the area of the shaded region under the standard normal curve. If convenient, use technology to find the area. . -0.7 0 1.2 The random variable x is normally distributed with mean = 174 and standard deviation = 20. Find the indicated probability. P(x > 155) Use the Standard Normal Table or technology to find the z-score that corresponds to the cumulative area or percentile. 0.2090 In a survey of U.S. women, the heights in the 20- to 29-year age group were normally distributed, with a mean of 64.2 inches and a standard deviation of 2.9 inches. Find the probability that a... The amounts of time per workout an athlete uses a stairclimber are normally distributed, with a mean of 20 minutes and a standard deviation of 5 minutes. Find the probability that a randomly selected... Find the positive z-score for which 12% of the distributions area lies between -z and z. Find the indicated z-score. The per capita energy consumption level (in kilowatt-hours) in Venezuela for a recent year can be approximated by a normal distribution, as shown in the figure. (a) What consumption level represents... The test scores for the analytical writing section of the Graduate Record Examination (GRE) can be approximated by a normal distribution, as shown in the figure. (a) What is the maximum score that... A population has a mean and a standard deviation . Find the mean and standard deviation of the sampling distribution of sample means with sample size n. = 45, = 15, n = 100 A population has a mean and a standard deviation . Find the mean and standard deviation of the sampling distribution of sample means with sample size n. = 1275, = 6, n = 1000 As the sample size increases, the standard deviation of the distribution of sample means increases. Determine whether the statement is true or false. If it is false, rewrite it as a true statement. The diameters (in inches) of four machine parts are 1.000, 1.004, 1.001, and 1.003. Use a sample size of 2. A population and sample size are given. (a) Find the mean and standard deviation of the... A water footprint is a measure of the appropriation of fresh water. The per capita water footprint in the United States for a recent year is approximately normally distributed, with a mean of 1.64... From 1871 through 2016, the mean return of the Standard & Poors 500 was 10.72%. A random sample of 38 years is selected from this population. What is the probability that the mean return for the... In a sample of 1000 fines issued by the city of Toronto for parking infractions, the mean fine was $47.12 and the standard deviation was $48.24. A random sample of size 55 is selected from this... Find the area of the indicated region under the standard normal curve. If convenient, use technology to find the area. 0.46 Find the area of the indicated region under the standard normal curve. If convenient, use technology to find the area. -2.35 -0.8 0 Find the indicated area under the standard normal curve. If convenient, use technology to find the area. To the right of z = 3.22 Find the critical value z c necessary to construct a confidence interval at the level of confidence c. c = 0.85 Find the critical value z c necessary to construct a confidence interval at the level of confidence c. c = 0.75 Find the critical value z c necessary to construct a confidence interval at the level of confidence c. c = 0.97 Use the values on the number line to find the sampling error. X = 3.8 u = 4.27 + 3.4 3.6 3.8 4.0 4.2 4.4 4.6 Use the confidence interval to find the margin of error and the sample mean. (6.17, 8.53) In a survey of 1000 U.S. adults, 700 think police officers should be required to wear body cameras while on duty. Construct a 99% confidence interval for the population proportion. Interpret the... In a survey of 1000 U.S. adults, 490 oppose allowing transgender students to use the bathrooms of the opposite biological sex. Construct a 90% confidence interval for the population proportion of... Construct (a) a 95% confidence interval and (b) a 99% confidence interval for the population proportion of college students who gave each response. Use the figure, which shows the results of a survey... You are analyzing the sample of car batteries in Exercise 21. The population standard deviation of the batteries reserve capacities should be less than 0.25 hour. Does the confidence interval you... The level of significance is the maximum probability you allow for rejecting a null hypothesis when it is actually true. Determine whether the statement is true or false. If it is false, rewrite it... To support a claim, state it so that it becomes the null hypothesis. Determine whether the statement is true or false. If it is false, rewrite it as a true statement. The statement represents a claim. Write its complement and state which is H 0 and which is H a . p < 0.45 Determine whether the hypothesis test is left-tailed, right-tailed, or two-tailed. H 0 : 8.0 H a : > 8.0 An amusement park claims that the mean daily attendance at the park is at least 20,000 people. Write the claim as a mathematical statement. State the null and alternative hypotheses, and identify... According to a recent survey, 73% of college students did not use student loans to pay for college. Write the claim as a mathematical statement. State the null and alternative hypotheses, and... According to a recent survey, 52% of college students used their own income or savings to pay for college. Write the claim as a mathematical statement. State the null and alternative hypotheses, and... A high school claims that its mean graduation rate is more than 97%. State H 0 and Ha in words and in symbols. Then determine whether the hypothesis test is left-tailed, right-tailed, or two-tailed.... A transportation network company claims that the mean travel time between two destinations is about 16 minutes. You work for one of the companys competitors and want to reject this claim. How would... A null hypothesis is rejected with a level of significance of 0.10. Is it also rejected at a level of significance of 0.05? Explain. Find the P-value for the hypothesis test with the standardized test statistic z. Decide whether to reject H 0 for the level of significance . Right-tailed test z = 2.46 = 0.10 Test the claim about the population mean at the level of significance a. Assume the population is normally distributed. Claim: 22500; = 0.01; = 1200 Sample statistics: x = 23,500, n = 45 Match the level of confidence c with the appropriate confidence interval. Assume each confidence interval is constructed for the same sample statistics. c = 0.88 (a) 54.9 59.2 59.5 (b) 55.2 57.2 to... Determine the minimum sample size required when you want to be 95% confident that the sample mean is within one unit of the population mean and = 4.8. Assume the population is normally distributed. Find the critical value(s) and rejection region(s) for the type of t-test with level of significance a and sample size n. Left-tailed test, = 0.10, n = 20 A scientist estimates that the mean carbon dioxide emissions per country in a recent year are greater than 150 megatons. You want to test this estimate. To do so, you determine the carbon dioxide... Explain how to determine whether a normal distribution can be used to approximate a binomial distribution. Explain how to test a population proportion p. As part of your work for an environmental awareness group, you want to test a claim that the mean amount of lead in the air in U.S. cities is less than 0.036 microgram per cubic meter. You find that... An employment information service claims the mean annual salary for home care physical therapists is more than $80,000. The annual salaries (in dollars) for a random sample of 12 home care physical... Determine whether a normal sampling distribution can be used. If it can be used, test the claim. Claim: p > 0.70; = 0.04. Sample statistics: p = 0.64, n = 225 A research center claims that at least 27% of U.S. adults think that the IRS will audit their taxes. In a random sample of 1000 U.S. adults in a recent year, 23% say they are concerned that the IRS... Test the claim about the population variance s 2 or standard deviation s at the level of significance a. Assume the population is normally distributed. Claim: 2 17.6; = 0.01. Sample statistics: s... A research center claims that at most 18% of U.S. adults online food purchases are for snacks. In a random sample of 1995 U.S. adults, 20% say their online food purchases are for snacks. At = 0.10,... Describe another way you can perform a hypothesis test for the difference between the means of two populations using independent samples with 1 and 2 known that does not use rejection regions. Sample 1: The average speed of 23 powerboats using an old hull design Sample 2: The average speed of 14 powerboats using a new hull design Classify the two samples as independent or dependent and... You interview a random sample of 100 adults. The results of the survey show that 59% of the adults said they live in ways that help protect the environment some of the time. At = 0.05, can you... An auto manufacturer claims that the variance of the gas mileages in a model of hybrid vehicle is 0.16. A random sample of 30 vehicles has a variance of 0.26. At a = 0.05, is there enough evidence to... Determine whether there is a perfect positive linear correlation, a strong positive linear correlation, a perfect negative linear correlation, a strong negative linear correlation, or no linear... To compare the dry braking distances from 60 to 0 miles per hour for two makes of automobiles, a safety engineer conducts braking tests for 23 models of Make A and 24 models of Make B. The mean... Two variables are given that have been shown to have correlation but no cause-and-effect relationship. Describe at least one possible reason for the correlation. Alcohol use and tobacco use. The mean ACT English score for 120 high school students is 20.1. Assume the population standard deviation is 6.8. The mean ACT reading score for 150 high school students is 21.3. Assume the... Construct a 99% confidence interval for the difference between the mean annual salaries of entry level architects in Denver, Colorado, and Los Angeles, California, using the data from Exercise 28.... A researcher wanted to know if using regular fertilizer or organic fertilizer will affect the yield of potatoes. He divided a large parcel of land into 10 small parcels and then randomly selected... In a survey of 1750 females ages 20 to 24 whose highest level of education is completing high school, 64.4% were employed. In a survey of 2000 males ages 20 to 24 whose highest level of education is... Which of the following values cannot be the probability of an event and why? 2.4 3/8 .63 .55 9/4 2/9 1.0 12/17 At = 0.01, can you support the claim that the proportion of newlywed Asians who have a spouse of a different race or ethnicity is greater than the proportion of newlywed whites who have a spouse of... A random sample of 2000 adults showed that 1320 of them have shopped at least once on the Internet. What is the (approximate) probability that a randomly selected adult has shopped on the Internet? The scatter plots show the results of a survey of 20 randomly selected males ages 24 35. Using age as the explanatory variable, match each graph with the appropriate description. Explain your... How many different outcomes are possible for 10 tosses of a coin?
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