statistics two tailed test

Question

The mean for the SATs for all high school students was 500, with a standard deviation of 100. 75 students from Cerritos were tested and they produced a mean of 510.

a. Who are the groups being compared/tested?

What is the dependent variable?

b. What are the null and research hypotheses?

c. what are the numbers needed for the z statistic?

d. What is the z statistic?

e. For a two tailed test at .05 significance, the critical area is +/- 1.96. What decision do we make?

Answer 1

a. The students from Cerritos and all of he high school students

SAT score

b. Ho: mean = 500

Ha: mean != 500

c. sample mean, population mean, population standard deviation, sample size

d.

z = (510 - 500)/(100/sqrt(75)) = 0.866

e. z < 1.96 so do to reject Ho.