Executives Of A Supermarket Chain Are Interested In The Amount Of Time That Customers Spend In The Stores During Shoppin 1 (28.59 KiB) Viewed 9 times
Executives Of A Supermarket Chain Are Interested In The Amount Of Time That Customers Spend In The Stores During Shoppin 2 (31.55 KiB) Viewed 9 times
Executives of a supermarket chain are interested in the amount of time that customers spend in the stores during shopping trips. The mean shopping time, spent by customers at the supermarkets has been reported to be 38 minutes, but executives have good reason to believe that it is different from 38 minutes. The executives hire a statistical consultant and ask her to perform a statistical test. To perform her statistical test, the consultant collects a random sample of shopping times at the supermarkets. She computes the mean of these times to be 43 minutes and the standard deviation of the times to be 12 minutes. Based on this information, complete the parts below.. (a) What are the null hypothesis H, and the alternative hypothesis H, that should be used for the test? HO (b) Suppose that the consultant decides to reject the nul hypothesis. What sort of error might she be making? Type I (c) Suppose the true mean shopping time spent by customers at the supermarkets is 46 minutes. Pal in the blanks to describe a Type 11 error. A Type 11 error would be rejecting 38 the hypothesis that us is less than or equal to when, in fact, ja is less than 12 H X 00 00 00 x 8 DID 0-0 DHD 2 G Submit Assignment
Question 4 d According to a report done by S&J Power, the mean lifetime of the light bulbs it manufactures is 53 months. A researcher for a consumer advocate group tests this by selecting 70 bulbs at random. For the bulbs in the sample, the mean lifetime is 52 months. It is known that the population standard deviation of the lifetimes is 4 months. Can we conclude, at the 0.10 level of significance, that the population mean lifetime, , of light bulbs made by this manufacturer differs from 53 months? Perform a two-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places, and round your responses as specified below. (If necessary, consult a list of formulas) (a) State the null hypothesis and the alternative hypothesis H H₂:0 H₁:0 (b) Determine the type of test statistic to use. (Choose one) (c) Find the value of the test statistic. (Round to three or more decimal places) 0 (d) Find the two critical values. (Round to three or more decimal places.) and (e) Can we conclude that the population mean lifetime of light bulbs made by this manufacturer differs from 53 months? OYes No H EM x O s x co B 0-0 010010 cla 000<0 0.0 2 5
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