Question

In: Statistics and Probability

The manager of a computer retails store is concerned that his suppliers have been giving him...

The manager of a computer retails store is concerned that his suppliers have been giving him laptop computers with lower than average quality. His research shows that replacement times for the model laptop of concern are normally distributed with a mean of 3.7 years and a standard deviation of 0.5 years. He then randomly selects records on 37 laptops sold in the past. Round the answers of following questions to 4 decimal places. What is the distribution of X ? X ~ N( , ) What is the distribution of ¯ x ? ¯ x ~ N( , ) What is the probability that one randomly selected laptop is replaced less than 3.6 years? For 37 laptops, find the probability that the average replacement time is less than 3.6 year. For part d), is the assumption of normal necessary? YesNo

Solutions

Expert Solution

Since sample size is more than 30 we use central limit theorem to find probability. Give thumb up. Thank you.


Related Solutions

The manager of a computer retails store is concerned that his suppliers have been giving him...
The manager of a computer retails store is concerned that his suppliers have been giving him laptop computers with lower than average quality. His research shows that replacement times for the model laptop of concern are normally distributed with a mean of 4.5 years and a standard deviation of 0.6 years. He then randomly selects records on 50 laptops sold in the past and finds that the mean replacement time is 4.3 years. Assuming that the laptop replacement times have...
The manager of a computer retails store is concerned that his suppliers have been giving him...
The manager of a computer retails store is concerned that his suppliers have been giving him laptop computers with lower than average quality. His research shows that replacement times for the model laptop of concern are normally distributed with a mean of 3.8 years and a standard deviation of 0.6 years. He then randomly selects records on 16 laptops sold in the past. What is the distribution of ¯xx¯? ¯xx¯ ~ N( ) What is the probability that one randomly...
The manager of a computer retails store is concerned that his suppliers have been giving him...
The manager of a computer retails store is concerned that his suppliers have been giving him laptop computers with lower than average quality. His research shows that replacement times for the model laptop of concern are normally distributed with a mean of 4.5 years and a standard deviation of 0.6 years. He then randomly selects records on 29 laptops sold in the past and finds that the mean replacement time is 4.2 years. Assuming that the laptop replacement times have...
The manager of a computer retails store is concerned that his suppliers have been giving him...
The manager of a computer retails store is concerned that his suppliers have been giving him laptop computers with lower than average quality. His research shows that replacement times for the model laptop of concern are normally distributed with a mean of 4 years and a standard deviation of 0.4 years. He then randomly selects records on 49 laptops sold in the past and finds that the mean replacement time is 3.8 years. Assuming that the laptop replacement times have...
The Python Question is as follows: You have been asked by a manager of a store...
The Python Question is as follows: You have been asked by a manager of a store to identify the items most commonly bought together (the manager would like to place these items in close proximity). You are given a file, receipts.txt , that contains the receipts of the last 1000 transactions in the following format, where each line of the file is a single receipt: eggs, bread, milk, lettuce cheese, milk, apples bread, milk bread, cheese, milk Write a function...
A sales manager for a company is concerned about possible differences in the popularity of his...
A sales manager for a company is concerned about possible differences in the popularity of his product in Western and Eastern Canada. In order to develop a marketing strategy, a survey of possible customers was conducted in each of these regions. West (x) Sample Size 600, Number who prefer the product 283 East (y) Sample Size 550, Number who prefer the product 218 (a) Is the product's popularity different for these two regions? Test at a = 0.05. (b) Estimate...
You have just been hired as the marketing manager at a small retail clothing store. In...
You have just been hired as the marketing manager at a small retail clothing store. In the past, the store has done all the inventory purchasing, marketing and sales promotions based on intuition. Of course, as a marketing professional, you know that this is not the best strategy. You must convince your new boss to use a more empirical approach based on marketing metrics. Write a few organized paragraphs explaining to your boss what marketing metrics should be used and...
Marvin is responsible for purchasing computers and accessories for his employer’s computer store. His cousin, David,...
Marvin is responsible for purchasing computers and accessories for his employer’s computer store. His cousin, David, sells computer accessories wholesale and asks him to send some business his way as he would certainly make it “worthwhile” for Marvin, if he does so. Marvin is responsible for the budget for the Purchasing Department and agrees to purchase items from David’s business but asks that he “pads” the invoice so that he can get his “cut” of the deal. David inflates the...
THE PEACH COMPUTER COMPANY Donald Bright, supply manager at the Peach Computer Company, was preparing his...
THE PEACH COMPUTER COMPANY Donald Bright, supply manager at the Peach Computer Company, was preparing his notes for a meeting to be held that afternoon. The meeting concerned the construction of a new $6 million, 120,000-square-foot building to be located near Dayton, Ohio. The principle issue to be discussed, and hopefully resolved, was what method of specification the firm should use in the purchase of its new building. When the requirement for the building first arose, the plant engineer at...
You’re a manager at a nonprofit. Your supervisee has been a planned-giving fundraiser there for five...
You’re a manager at a nonprofit. Your supervisee has been a planned-giving fundraiser there for five years. Four years ago, his performance was poor because he was undergoing chemotherapy. Since then, it’s improved to average but, in the past few months has declined severely again—He’s raised only half as much money as before. He explains that his cancer has recurred and has spread to his lymph nodes, so he’s in the middle of a six-month round of chemotherapy and his...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT