According to a study several years ago by the Personal Communications Industry Association, the average wireless phone user earns $62,600 per year. Suppose a researcher believes that the average annual earnings of a wireless phone user are now higher and he sets up a study to prove his theory. He randomly samples 48 wireless phone users and finds the average annual salary for this sample is $64,820 with a standard deviation of $7,810. Use to test the researcher’s theory.

Question

According to a study several years ago by the Personal Communications Industry Association, the average wireless phone user earns $62,600 per year.  Suppose a researcher believes that the average annual earnings of a wireless phone user are now higher and he sets up a study to prove his theory.  He randomly samples 48 wireless phone users and finds the average annual salary for this sample is $64,820 with a standard deviation of $7,810.  Use   to test the researcher’s theory.

PsyDAG · Answer

Z = (mean1-mean2)/sqrt(SEm1^2 + SEm2^2)

SEm = SD/sqrt(n-1)

If only one SD is known, it can be used alone.

Look up Z in table in the back of your stats text labeled something like "areas under normal distribution to find proportion.

josh · Answer

HA idk

Anonymous · Answer

-1.97

aimen · Answer

this question is correct or wrong?