Suppose you drew a random sample from a population where the

Suppose you drew a random sample from a population where the mean is 100. the standard error of the sampling distribution is 10. The mean for your sample is 80. What could you conclude about your sample?

A. the sample mean does not occur very often by chance in the sampling distribution of means and probably did not come from the given population

B. The sample mean occurs very often by chance in the sampling distribution of means and probably did not come from the given population

C. The sample mean does not occur very often by chance in the sampling distribution of means but probably did come from the given population

D. the sample mean occurs very often by chance in the sampling distribution of means and probably did come from the given population

Solution

Suppose you drew a random sample from a population where the mean is 100. the standard error of the sampling distribution is 10. The mean for your sample is 80. What could you conclude about your sample?

By assuming the sample size is very large,

test value Z=(80-100/10 = -2

-2 < -1.96, THE 5% LEVEL

REJECT THE NULL HYPOTHESIS AT 5% LEVEL

A. the sample mean does not occur very often by chance in the sampling distribution of means and probably did not come from the given population

B. The sample mean occurs very often by chance in the sampling distribution of means and probably did not come from the given population

C. The sample mean does not occur very often by chance in the sampling distribution of means but probably did come from the given population

D. the sample mean occurs very often by chance in the sampling distribution of means and probably did come from the given population