It is well known that car buyers often add accessories to their new cars. A sample of 179 Ottawa purchasers yielded a sample mean of $5000 worth of accessories added to the purchase above the base sticker price. Suppose the cost of accessories purchased for all Ottawa has a standard deviation of $1500. (a) Calculate a 95% confidence interval for the average cost of accessories on Ottawa. – Section Break - (b) Determine the margin of error in estimating the average cost of accessories on Ottawa. (c) What sample size would be required to reduce the margin of error by 50%?

It is well known that car buyers often add accessories to their new cars. A sample of 179 Ottawa purchasers yielded a sample mean of $5000 worth of accessories added to the purchase above the base sticker price. Suppose the cost of accessories purchased for all Ottawa has a standard deviation of $1500. (a) Calculate a 95% confidence interval for the average cost of accessories on Ottawa. – Section Break - (b) Determine the margin of error in estimating the average cost of accessories on Ottawa. (c) What sample size would be required to reduce the margin of error by 50%?

ENGR.ECONOMIC ANALYSIS

14th Edition

ISBN:9780190931919

Author:NEWNAN

Publisher:NEWNAN

Chapter1: Making Economics Decisions

Section: Chapter Questions

Problem 1QTC

See similar textbooks

Similar questions

2. The average hour spent in computer by 20 senior high school students during online class is 7 hours with a standard deviation of 2 hours. Construct a 98% confidence interval of the average hour spent by all senior high school students. Identify the width of the interval. 20
a. 36 Out of 100 persons interviewed are familiar with the tax incentive given by the governmenti for installing solar panel, construct 96% confidence interval for true proportion. b. The average wages of 25 employees of a company are RS. 2500 with standard deviation of Rs. 250. Assuming wages to be normally distributed, calculate 98% confidence upper bound for the average wages and interpret it.
The average cost of tuition plus room and board for a small private liberal arts college is reported to be $8500 per term but I financial administrator boys that the average cost is half a study conducted using 350 small liberal arts colleges showed that the average cost per term is $8745 the population standard deviation is $1200 let a =0.05.what is the p-value for this test
A sports shop selects a random sample and records the sales of items made in China and thosemade in America. Country of origin n mean St.Deviation China 50 22.5 9.75 America 33 33.15 11.6 What is the SE Mean for the sales from China?
10. 7 students were asked how many pencils they had. The responses were 2, 5, 8, 3, 1, 6, and 4. a. Calculate the sample mean 8. Find the sample standard deviation C Find the Q1, Q3, and the interquartile range.
Question: In a certain factory there are two independent processes manufacturing the same item. The average weight in a sample of 250 items produced from one process is found to be 120 ozs. with a standard deviation of 12 ozs. while the corresponding figures in a sample of 400 items from the other process are 124 and 14. Obtain the standard error of difference between the two sample means. Is this difference significant ? Also find the 99% confidence limits for the difference in the average weights of items produced by the two processes respectively.
Suppose a baker wants to know, on average, how many pastries they sell in a day. They sampled over 4 days. On the first day they sold 10, on the second day they sold 12, on the third day they sold 18, and on the fourth day they sold 16. The population standard deviation of pastry sales is 3. What is the point estimate (average) number of pastries sold? 26 08 056 O 14 Nex
K The first statistics exam had a mean of 71 and a standard deviation of 15 points; the second had a mean of 82 and a standard deviation of 5 points. Anna scored a 84 on both tests. Megan scored 94 on the first exam and 74 on the second. They both totaled 168 points on the two exams, but Anna claims that her total is better. Explain. The total of Anna's z-scores is, which is greater than Megantotal of (Round to one decimal place as needed.)
4.43 A firm wishes to estimate the mean number of operating hours of a particular type of lightbulb within 10 operating hours (plus or minus) and with 95% confidence. On the basis of previous knowledge with this type of lightbulb, the firm knows o = 30 h. How large a sample would the firm take? Ans. 35
Question of the day. The mean weekly sales of the chocolate bar in candy stores was 146-3 bars per store. After an advertising campaign the mean weekly sales in 22 stores for a typical week increased to 153-7 and showed a standard deviation of 17-2. Was the advertising campaign successful?
A total of 280 observations of Bob Ramos, an assembly-line worker, were made over a 40-hour work week. The sample also showed that Bob was busy working (assembling the parts) during o 230 bservations. (Round all intermediate calculations to at least two decimal places before proceeding with further calculations.) The number of observations that need to be taken of Bob to be 99% confident with 4% acceptablee error=
Question: Godrej soap manufacturing company was distributing a particular brand of soap through a large number of retail shops. Before a heavy advertisement campaign, the mean sales per week per shop was 140 dozens. After the campaign, a sample of 26 shops was taken and the mean sales was found to be 147 dozens with standard deviation 16. Can you consider the advertisement effective?