Question

224 - CHAPTER 8 5. A researcher hypothesizes that people who listen to music via headphones have greater hearing loss and will thus score lower on a hearing test than those in the general population. On a stand- ard hearing test, the overall mean is 22.5. The re- searcher gives this same test to a random sample of 12 individuals who regularly use headphones. Their scores on the test are 16, 14, 20, 12, 25, 22, 23, 19, 17, 17, 21, 20. a. Is this a one-or two-tailed test? b. What are H, and H, for this study? c. Compute tobt d. What is ty? e. Should H, be rejected? What should the researcher conclude? f. Determine the 95% confidence interval for the population mean, based on the sample mean.

Answer 1

ANSWER me researcher hypothesizes that people who listen to music Va, heart phones have greater hearing loss and will thels Score lowey hack on a hearing test than those in the general populason Derall mean is 22.5 random sampe Of Spa & individuals who regularly use the headphones Scores on test are 16,14, 20, 12 ,25,23 ,19,17,17,21,20 One-OM two - talled test: : people who listen music score bwey on hearing test than those in general poplilation .:This is one tari test Ho and la is 40: Neu hypothesis : 4:22.5 Alternative hypoveds Id2.22.5 Single sample test Following is the screen shot of excel for performing single sample t test: A B C D E F Score HI 17 14 Hypothesis Test: Mean vs. Hypothesized Value data input summary input OK Sheet1!$B$1:$B$13 . Input Range Clear Cancel Alternative: less than 22.5 - Hypothesized mean 1 Help

Hypothesis res : Mean vs Hypothesized vabe 29.500 hypothesized value 18.933 mean score 3.78G Std.dev 1:093 sid. error lan 0.0032 16.428 21.239 2.405 p-value one toiled) By Imreler confidence interval 95% locuer confidence Interval 95%. upper margin of error (0) Test statistics t=x- sin : -3.35 di tov? dp-n-1 = 11 Critical value ter = -1.796 Ho be rejected : test stastics > critical valve, so reject bull bypophesis. Researcher Conclude people who listen murc score lower on a thearing test than those in the goneral population 951. CI is Et tam - (16.428,21,239) Required Ca is (16,428,21,2399. *** Thanking you $)