Eddie Clauer sells a wide variety of outdoor equipment and clothing. The company sells both through mail order and via the internet. Random samples of sales receipts were studied for mail order sales and internet sales, with the total purchase being recorded for each sale. A random sample of 7 sales receipts for mail order sales results in a mean sale amount of $64.90 with a standard deviation of $18.75. A random sample of 11 sales receipts for internet sales results in a mean sale amount of $83.10 with a standard deviation of $27.25. Using this data, find the 90 % confidence interval for the true mean difference between the mean amount of mail order purchases and the mean amount of internet purchases. Assume that the population variances are not equal and that the two populations are normally distributed. Step 1 of 3: Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places. Answer How to enter your answer (opens in new window) Tables Keypad Keyboard Shortcuts

For a sample of 120 businesses, the average profit they generate in a month is $54,000 with a standard deviation of $8,800. Find the sample standard deviation for the distribution.

Airline Fares. The mean airfare for flights departing from Buffalo Niagara International Airport during the first three months of 2017 was $320.51. Assume the standard deviation for this population of fares is known to be $80. Suppose a random sample of 60 flights departing from Buffalo Niagara International Airport during the first three months of 2018 is taken. If the mean and standard deviation of the population of airfares for flights departing from Buffalo Niagara International Airport didn’t changed between the first three months of 2017 and the first three months of 2018, what is the probability the sample mean will be within $20 of the population mean cost per flight? What is the probability the sample mean will be within $10 of the population mean cost per flight?

A bridal gown shop owner owns a store in San Francisco and a store in Redwood city. She is trying to figure out if clients tend to spend the same amount at both stores. She takes a random sample of 25 purchases from each store, and find the San Francisco store has a mean amount spent of $2500 with a standard deviation of $1500. The Redwood City store has a mean amount spent of $2000 with a standard deviation of $1000. Use a significance level of 10% to determine if the clients at the two stores spend the same amounts. State:  Plan: Do: Conclude:

An insurance company crashed four cars in succession at 5 miles per hour. The cost of repair for each of the four crashes was ​$421​, ​$469​, ​$416​, ​$232   . Compute the​ range, sample​ variance, and sample standard deviation cost of repair.

A marketing consultant is hired by a major restaurant chain wishing to investigate the preferences and spending patterns of lunch customers. The CEO of the chain hypothesized that the average customer spends at least $13.50 on lunch. A survey of 25 customers sampled at one of the restaurants found the average lunch bill per customer to be ?¯=$14.50 . Based on previous surveys, the restaurant informs the marketing manager that the standard deviation is ?=$3.50 . To address the CEO’s conjecture, the marketing manager carried out a hypothesis test of ?0:?=13.50 vs. ??:?>13.50 and obtained a ?‑value = 0.77. The marketing chooses a significance level of ?=0.10. If he uses this significance level throughout his work, how often will he reject a true null hypothesis? Group of answer choices a.He will reject 10% of all true null hypotheses. b. He will reject 1% of all true null hypotheses. c. He will reject 5% of all true null hypotheses. d. He will not reject 10% of all true null…

According to the Vivino website, suppose the mean price for a bottle of red wine that scores 4.0 or higher on the Vivino Rating System is $32.48. A New England-based lifestyle magazine wants to determine if red wines of the same quality are less expensive in Providence, and it has collected prices for 64 randomly selected red wines of similar quality from wine stores throughout Providence. The mean and standard deviation for this sample are $30.15 and $12, respectively. (a) Develop appropriate hypotheses for a test to determine whether the sample data support the conclusion that the mean price in Providence for a bottle of red wine that scores 4.0 or higher on the Vivino Rating System is less than the population mean of $32.48. (Enter != for # as needed.) Ho: H: (b) Using the sample from the 64 bottles, what is the test statistic? (Round your answer to three decimal places.) Using the sample from the 64 bottles, what is the p-value? (Round your answer to four decimal places.) p-value =…

Suppose two graduating seniors, one a marketing major and one an accounting major, are comparing job offers. The accounting major has an offer for $53,000 per year, and the marketing major has an offer for $49,000 per year. Summary information about the distribution of the offers is shown below:   Accounting:  mean:  50000                 standard deviation:  1500 Marketing:  mean:  45500                   standard deviation:  1000   Which offer is more attractive and why?

A report about how American college students manage their finances includes data from a survey of college students. Each person in a representative sample of 793 college students was asked if they had one or more credit cards and if so, whether they paid their balance in full each month. There were 500 who paid in full each month. For this sample of 500 students, the sample mean credit card balance was reported to be $825. The sample standard deviation of the credit card balances for these 500 students was not reported, but for purposes of this exercise, suppose that it was $205. Is there convincing evidence that college students who pay their credit card balance in full each month have a mean balance that is lower than $907, the value reported for all college students with credit cards? Carry out a hypothesis test using a significance level of 0.01.   State the appropriate null and alternative hypotheses. H0: ? = 907 Ha: ? < 907 H0: ? = 907 Ha: ? > 907      H0: ? < 907…

the mean charge for satellite television for a sample of households was $87.50 per month, with a standard deviation of $14.50 per month. Estimate the percent of satellite television charges between $73.00 and $102.00