Concept explainers
In Problem 13.6 on page 494, a prospective MBA student wanted to predict starting salary upon graduation, based on program per-year tuition. The data are stored in FTMBA.
a. Construct a
b. Construct a
c. Why is the interval in (a) narrower than the interval in (b)?
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BASIC BUSINESS STATISTICS-STUD.SOLN.MAN
- A survey asked senior executives at large corporations their opinions about the economic outlook for the future. One question was, "Do you think that there will be an increase in the number of full-time employees at your company over the next 12 months?" In the current survey, 232 of 400 executives answered Yes, while in a previous year survey, 168 of 400 executives had answered Yes. Provide a 95% confidence interval estimate for the difference between the proportions at the two points in time. (Use current year - previous year. Round your answer to four decimal places.) to What is your interpretation of the interval estimate? The 95% confidence interval ---Select--- v zero. This suggests that the proportion of executives who are predicting an increase in full-time jobs for the current year is --Select-- v than the proportion of executives who were predicting an increase in full-time jobs for the previous year. Need Help? Read It Watch Itarrow_forwardA survey asked senior executives at large corporations their opinions about the economic outlook for the future. One question was, "Do you think that there will be an increase in the number of full-time employees at your company over the next 12 months?" In the current survey, 220 of 400 executives answered Yes, while in a previous year survey, 172 of 400 executives had answered Yes. Provide a 95% confidence interval estimate for the difference between the proportions at the two points in time. (Use current year – previous year. Round your answer to four decimal places.) to What is your interpretation of the interval estimate? The 95% confidence interval ---Select--- O zero. This suggests that the proportion of executives who are predicting an increase in full-time jobs for the current year is ---Select--- than the proportion of executives who were predicting an increase in full-time jobs for the previous year.arrow_forwardchapter: ESTIMATIONarrow_forward
- In simple linear regression, at what value of the independent variable, X, will the 95% confidence interval for the average value of Y be narrowest? At what value will the 95% prediction interval for the value of Y for a single n ew observation be narrowest?arrow_forwardImport the data from the Hill City Excel file into Minitab.You are trying to predict Price.Note: Mtn View=1 if there is a mountain view, 0 otherwise. The rest of the variables should be self explanatory. 1.Perform an F Test for overall significance of the model 2.Perform a T test for slope for the age variable 3. Find a 95% confidence interval for the slope of the SqFeet variable4. Create a prediction, CI, and PI for 1 new set of x values (any valid numbers you want), and interpret each.5. Run the residual plots and indicate if they show any problems with the model.arrow_forwardA Businessweek/Harris poll asked senior executives at large corporations their opinions about the economic outlook for the future. One question was, "Do you think that there will be an increase in the number of full-time employees at your company over the next 12 months?" In the current survey, 230 of 500 executives answered Yes, while in a previous year survey, 196 of 500 executives had answered Yes. Provide a 95% confidence interval estimate for the difference between the proportions at the two points in time (to 4 decimals). Do not round your intermediate calculations. .0000 to .1366 What is your interpretation of the interval estimate? Approximately ( 14% more executives are predicting an increase + in full-time jobs. The confidence interval shows the difference may be from 14% to 0%arrow_forward
- A Businessweek/Harris survey asked senior executives at large corporations their opinionsabout the economic outlook for the future. One question was, “Do you think that therewill be an increase in the number of full-time employees at your company over the next12 months?” In the current survey, 220 of 400 executives answered Yes, while in a previous year survey, 192 of 400 executives had answered Yes. Provide a 95% confidenceinterval estimate for the difference between the proportions at the two points in time. Whatis your interpretation of the interval estimate?arrow_forwardA Businessweek/Harris survey asked senior executives at large corporations their opinions about the economic outlook for the future. One question was, "Do you think that there will be an increase in the number of full-time employees at your company over the next 12 months?" In the current survey, 240 of 500 executives answered Yes, while in a previous year survey, 198 of 500 executives had answered Yes. Provide a 95% confidence interval estimate for the difference between the proportions at the two points in time (to 4 decimals). Use z-table. toarrow_forwardThe following data represent the commute time (in minutes) x and a score on a well-being survey y. The equation of the least-squares regression line is y = -0.0480x + 69.1570 and the standard error of the estimate is 0.3036. Complete parts (a) through (e) below. X y 40 55 77 110 D 10 20 30 69.0 68.1 67.5 67.2 66.2 65.9 63.8 (a) Predict the mean well-being index composite score of all individuals whose commute time is 35 minutes. y=(Round to two decimal places as needed.) (b) Construct a 90% confidence interval for the mean well-being index composite score of all individuals whose commute time is 35 minutes. Lower Bound Upper Bound ... (Round to two decimal places as needed.) (Round to two decimal places as needed.) (c) Predict the well-being index composite score of Jane, whose commute time is 35 minutes. y=(Round to two decimal places as needed.)arrow_forward
- 1. a. You want to estimate the mean hourly yield for a process that manufactures an antibiotic. You observe the process for 50 hourly periods chosen at random, with the results ?̅= 31 ounces per hour and ? = 3. Estimate the mean hourly yield for the process using a 90% and 95% confidence interval. no 2 di fotoarrow_forward8.2 Question 3). According to the February 2008 Federal Trade Commission report on consumer fraud and identity theft, Arkansas had 1,601 complaints of identity theft out of 3,482 consumer complaints ("Consumer fraud and," 2008). Calculate a 90% confidence interval for the proportion of identity theft in Arkansas.arrow_forwarda. interpret the corresponding 95% confidence intervals for both Birth weight and Age. b. What is the predicted average SBP of an infant born with birth weight 8lbs (128oz) measured at 3 days old? c. Calculate the Pearson correlation between Age and Birth weight, and test if this correlation is significant at the 0.05 level. Does this answer surprise you, why or why not?arrow_forward
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