In this problem, assume that the distribution of differences is approximately normal. Note: For degrees of freedom d.f. not in the Student's t table, use the closest d.f. that is smaller. In some situations, this choice of d.f. may increase the P-value by a small amount and therefore produce a slightly more "conservative" answer. Are America's top chief executive officers (CEOs) really worth all that money? One way to answer this question is to look at row B, the annual company percentage increase in revenue, versus row A, the CEO's annual percentage salary increase in that same company. Suppose a random sample of companies yielded the following data: B: Percent increase for company 24 25 27 18 6 4 21 37 A: Percent increase for CEO 21 23 24 14 −4 19 15 30 Do these data indicate that the population mean percentage increase in corporate revenue (row B) is different from the population mean percentage increase in CEO salary? Use a 5% level of significance. (Let d = B − A.) (a)What is the level of significance?=__ What is the value of the sample test statistic? (Round your answer to three decimal places.)=__

Suppose the table below gives the average tuition and fees at 2-year and 4-year state schools in a particular state. Values are adjusted to 2019 dollars. Academic Year 4-year state school 2-year state school 2005-06 $5,904 $2,661 2006-07 $6,066 $2,539 2007-08 $6,289 $2,604 2008-09 $7,222 $2,901 2009-10 $7,738 $3,065 2010-11 $8,035 $3,117 2011-12 $8,154 $3,108 2012-13 $8,497 $3,075 2013-14 $8,578 $3,025 2014-15 $9,390 $3,326 2015-16 $10,004 $3,504 2016-17 $10,474 $3,663 2017-18 $10,789 $3,830 2018-19 $10,874 $3,859 2019-20 $10,900 $3,907 Here is a graph of the information from the table.   a. What is the absolute change in tuition and fees at this state's four-year institutions from 2005-06 to 2019-20? b. What is the relative change in tuition and fees at this state's four-year institutions from 2005-06 to 2019-20? Round to the nearest whole percentage…

A County Board of Supervisors has appointed an urban planning committee to evaluate proposed community development projects. The committee is analyzing, among other things, data on household incomes in two cities within the county. They have collected data on the income of 80 households in each of the two cities. The histograms below show the distributions of the two sets of incomes (in thousands of dollars). Each histogram shows household income on the horizontal axis and number of households on the vertical axis. The means and standard deviations for the data sets are also given. City A City B 25- 25 - 20+ 20- 15- 15- 10+ 10- 5+ 5- 0- 10 20 30 40 50 60 70 80 90 100 10 20 30 40 50 60 70 80 90 100 City A mean: 38.13 thousand dollars City B mean: 55.13 thousand dollars City A standard deviation: 20.84 thousand dollars City B standard deviation: 14.71 thousand dollars The committee wants to use the Empirical Rule to make some approximations about both data sets. Unfortunately, it is…

Members of the student council are seling bagels during each class period of the school day for a fundrasier. Yu-na made a scatter plot to see if there was a relationship between the class period and the number of bagels sold.Yu-na draws a line of best fit. Which of these lines is the best model for the data?

The table below shows the grades of the 20 students of a martial arts class. There are three grades: satisfactory(S), unsatisfactory(U), and incomplete(I) Question: Which measure of central tendency is appropriate for the variable? Mode Median Mean

It is possible for the value of the median to be greater that the value of the mode.  a. True b. False

Given the weekly price and quantity (Qx and (Px) data for Andy’s ice cream over the past 12 weeks and the price of another ice-cream flavor (Po) as: Qx 84 82 85 83 82 84 87 81 82 79 82 78 Px 8.50 9.00 8.75 9.25 9.50 9.25 8.25 10.00 10.00 10.50 9.50 10.25 Po 5.25 6.00 6.00 6.50 6.25 6.25 5.25 7.00 7.25 7.25 6.75 7.25 a. Use excel regression to estimate the weekly demand for Andy’s ice-cream (attach the output of the regression estimate (Hint: Use regression in excel to find the estimated demand function: Enter the data in excel, click on Data Analysis, and use the regression command). b. Are the coefficients on the two prices statistically significantly different from zero at the 5% significance level? How do you know? c. What the R2? d. Explain what R2 means.

A statistics instructor would like to know whether it is worthwhile to require students to do weekly homework assignments. For one section of the statistics course, homework is assigned, collected and graded each week. For another section, the same problems are suggested each week, but the students are not required to turn in their homework. At the end of the semester, all students take the same final exam. The score distribution for the two sections are as follows:   With Homework          12      15        17        5         10 No Homework             12      21        28        25        14          Do these data indicate a significant difference between the score distributions for students with homework versus students with no homework? Test at the 5% level of significance.

The amount of time adults spend watching television is closely monitored by firms because this helps to determine advertising pricing for commercials. Complete parts (a) through (d). ..... (a) Do you think the variable "weekly time spent watching television" would be normally distributed? If not, what shape would you expect the variable to have? A. The variable "weekly time spent watching television" is likely normally distributed. B. The variable "weekly time spent watching television" is likely symmetric, but not normally distributed. C. The variable "weekly time spent watching television" is likely uniform, not normally distributed. D. The variable "weekly time spent watching television" is likely skewed right, not normally distributed. E. The variable "weekly time spent watching television" is likely skewed left, not normally distributed. (b) According to a certain survey, adults spend 2.35 hours per day watching television on a weekday. Assume that the standard deviation for "time…

Mariah Jacobsen is the marketing manager at ABC Electronics, a major consumer electronics supplier in the northwest. Over the last five years, sales of the company's flagship product - the Wizer Anonymizer (the WA) - have been 45000, 45500, 44500, 46000 and 44000 units. This rate of sales is considered average for the product over the last twenty years or so. Ms. Jacobsen believes that the distribution of the WA's sales is normal with a standard deviation of 1500 units. If she were asked to make a forecast of next year's sales to upper management, what is the likelihood that she would be correct if she predicts sales between 43000 and 46000?