Answer to Question #1554 in Statistics and Probability for Misty cooke

Question

& 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 standard hearing test, the overall mean for the general population is 22.5. The researcher gives this same test to a random sample of 12 individuals who regularly use headphones. Their scores on the test are 15, 14, 20, 20, 25, 22, 21, 19, 16, 17, 21, 22.

Answer 1

a. t-test must be used, due to unknown variance.

b. This is a one tailed test because the prediction is that the private high
school students will have higher scores, thus there is a bias

c. H0: m<22.5;

Ha: m >=22.5

d.

Mn=19.33

M=22.5, Sn=3.257, n=12

Tobt=√(n)(Mn-M)/Sn=-3.368

e.We accept the hypothesis, because tobt<tcv. And the conslusion is 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.