4) A study of irrelevant speech effects examined a sample of 72 subjects. They performed a memorization task under two conditions (1) with irrelevant background speech and (2) in silence. Descriptive statistics on the relative difference in error rates (RDER) for the two conditions yielded x=79.2 percent and s=64.2 percent. Suppose the researchers theorize that the true standard deviation of the RDER values differs from 60 percent. do B-D

b. Compute the test statistics. x^2= (Round to two decimal places as needed.)

c. Find the rejection region of the test using a=0.05

D. find P-Value:

5) Amusia is a congenital disorder that adversely impacts one's perception of music. A study examined the pitch memory of individuals diagnosed with amusia. Each in a sample of 23 amusiacs listened to a series of tone pairs and was asked to determine if the tones were the same or different. In the first trial, the tones were separated by 3 ; in a second trial, the tones were separated by 7 seconds. The difference in accuracy scores for the two trials was determined for each amusiac (where the difference in the score on the first trial minus the score on the second trial). The mean score was 0.14 with a standard deviation of 0.17 . find t and p value B) Carry out the test using a=0.05

t=_______

The p-vaule of this test is _____

6) A study was conducted to see if people who use the Internet have also paid to download music. In a representative sample of 716 adults who use the Internet, 474 admitted that they have paid to download music. Let p represent the true proportion of all Internet-using adults who have paid to download music.

A) Compute a point estimate of p

The point estimate of p is

C) . Compute the test statistic

z=

D) Find the rejection region for the test if =0.05.

z>____

e. Find the p-value for the test.

p-value=