Question

In: Math

A NAPA auto parts supplier wants information about how long car owners plan to keep their...

A NAPA auto parts supplier wants information about how long car owners plan to keep their cars. a simple random sample of 31 car owners results in a mean of 7.01 years and a standard deviation of 3.74 years, respectively. Assume the sample is drawn from a normally distributed population.

a) Find a 95%confidence interval estimate of the mean.

b) Find a 95% confidence interval estimate of the population standard deviation.

c) If several years pass and you want to conduct a new survey to estimate the mean length of time that car owners plan to keep their cars, how many randomly selected cars owners must you survey? Assume you want 99% confidence that the sample mean is within 0.25 year of the population mean,also assume the standard deviation is 3.74 years.

Solutions

Expert Solution


Related Solutions

In the service department of the NAPA (National Auto Parts Association), mechanics requiring parts for auto...
In the service department of the NAPA (National Auto Parts Association), mechanics requiring parts for auto repair or service present their request forms at the parts department counter. The parts clerk fills a request while the mechanic waits. Mechanics arrive in a random (Poisson) fashion at the rate of 60 per hour, and a clerk can fill requests at the rate of 20 per hour (exponential). If the cost for a parts clerk is $20 per hour and the cost...
Question No.1    An auto parts supplier sells Hardy-brand batteries to car dealers and auto mechanics....
Question No.1    An auto parts supplier sells Hardy-brand batteries to car dealers and auto mechanics. The annual demand is approximately 1500 batteries. The supplier pays 25 R.O for each battery and estimates that the annual holding cost is 30% of the battery's value. It costs approximately 30 R.O to place an order. The supplier currently orders 125 batteries per month. a. Determine the EOQ. b. How many orders will be placed per year using the EOQ? c. Determine the...
Question No.1    An auto parts supplier sells Hardy-brand batteries to car dealers and auto mechanics....
Question No.1    An auto parts supplier sells Hardy-brand batteries to car dealers and auto mechanics. The annual demand is approximately 1500 batteries. The supplier pays 25 R.O for each battery and estimates that the annual holding cost is 30% of the battery's value. It costs approximately 30 R.O to place an order. The supplier currently orders 125 batteries per month. a. Determine the EOQ. b. How many orders will be placed per year using the EOQ? c. Determine the...
The following information relates to Questions 1-6. Modern Auto, an automobile parts supplier, has made an...
The following information relates to Questions 1-6. Modern Auto, an automobile parts supplier, has made an offer to acquire Sky Systems, creator of software for the airline industry. The offer is to pay Sky Systems’ shareholders the current market value of their stock in Modern Auto’s stock. The relevant information it used in those calculations is given below: Modern Auto Sky Systems Share price $40 $25 Shares outstanding (millions) 40 15 Earnings (millions) $100 $30 Although the total earnings of...
O’Reilly Auto Parts sells parts to Rick’s Car Repair with a rebate of 2% on purchases...
O’Reilly Auto Parts sells parts to Rick’s Car Repair with a rebate of 2% on purchases up to $60,000 and 3% on purchases above $60,000 if Rick’s purchases for the year exceed $200,000. In the past, Rick’s normally purchases $300,000 in parts during a calendar year. On January 1, 2018, Rick’s purchased $74,000 of parts. The journal entry by O’Reilly to record the sale includes a a. debit to Accounts Receivable for $74,000. b. credit to Sales Revenue for $72,380....
You have a contract with an auto parts supplier to provide spark plugs, and you guarantee...
You have a contract with an auto parts supplier to provide spark plugs, and you guarantee no more than 2% will be faulty. You believe your manufacturing process works and the error rate is actually 1% or even less. Your customer just returned a shipment, saying that they selected 20 at random and found 2 faulty, an error rate of 10%. Was the customer justified in returning the shipment (and not paying)? You ask your chief statistician the probability that...
You recently went to work for Allied Components Company, a supplier of auto repair parts used...
You recently went to work for Allied Components Company, a supplier of auto repair parts used in the after-market with products from Daimler AG, Ford, Toyota, and other automakers. Your boss, the CFO, has just handed you the estimated cash flows for two proposed projects. Project L involves adding a new item to the firm’s ignition system line; it would take some time to build up the market for this product, so the cash inflows would increase over time. Project...
You recently went to work for Allied Components Company, a supplier of auto repair parts used...
You recently went to work for Allied Components Company, a supplier of auto repair parts used in the after-market with products from Daimler AG, Ford, Toyota, and other automakers. Your boss, the chief financial officer (CFO), has just handed you the estimated cash flows for two proposed projects. Project L involves adding a new item to the firm’s ignition system line; it would take some time to build up the market for this product so that the cash inflows would...
You recently went to work for United Motors Company, a supplier of auto repair parts used...
You recently went to work for United Motors Company, a supplier of auto repair parts used in the after-market with products from Dodge, Fiat, Jeep, and other auto makers. Your boss, the chief financial officer (CFO), has just handed you the estimated cash flows for two proposed projects. Project X involves adding a new item to the firm’s ignition system line; it would take some time to build up the market for this product, so the cash inflows would increase...
You are given an old car by your uncle, who wants you to keep it in...
You are given an old car by your uncle, who wants you to keep it in working condition so that you can hand it off to your younger brother in three years. It will cost you $1,500 per year to keep it in working condition for your brother. If you skip maintenance altogether, the car will die after two years, but you can pocket the maintenance costs. a. What will you be tempted to do? Not do the maintenance, because...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT