Question

Libel In a random sample of four mobile devices, the mean repair cost was $60.00 and the standard deviation was $13.50. Assume the population is normally distrbuted and use at distribution to find the margin of error and construct a 90% confidence interval for the population mean. Interpret the results ol The 90% confidence interval for the population mean pis (C. (Round to two decimal places as needed.) The margin of error iss (Round to two decimal places as needed) Interpret the results. Choose the correct answer below A OA With 90% confidence, it can be said that the population mean repair cost is between the bounds of the confidence interval OB. If a large sample of mobile devices are taken approximately 90% of them will have ropair costs between the bounds of the confidence interval OC. It can be said that 90% of mobile devices have a repair cost between the bounds of the confidence interval OD. With 90% confidence, it can be said that the repair cost is between the bounds of the confidence interval extf hefo Click to select your answer(s). matid ther butiran nh o 2

Answer 1

men *to e candom sample of four mobile devicee, the repair cost was $60.00 deviation Ś 13:50 el = $60.00 S.D. 13,50 n=4 and the standard coal (0) The 90% confidence i's, internal for the populalion mean de 01 72/2 = 1.645 confidence Internal is oll - Zx/2x SD no allt 22/₂8 SD To Call (60- 1.6458 13.50 2 Got 1.645X 3.50 2 481896259 71.10375 The margin of emor is ts..05 3.182,- critical value [ Here we Calculate mitical value using t-distributh one posieb je said in Question Margin of enor Coriticen yolue x standard deviath. for 3:18 2 x (13150/14) sempat 421957 21:4785 2 N(0,1) of known, the lly immate. and 2 1,000 ana as drawn nice.)

(3) Cotra moet the results B. JF a Jorge sample of mobile devices and faven approximalely 90%. of them will have mepair costs beln the bounds of the confidence interval., XEN