Statistics
posted by Sue on .
The national centre of health statistics reports that the mean systolic blood pressure for males 3544
years of age is 128 and a standard deviation of 15. A group of 50 executives selected at random are tested and found to have an avarage of 132.3. Is there statistical evidence that the executives have a different blood pressure than the population? Use significant level of 0.05. Solve using a confidence interval approach or a hypothesis test.

If you use a onesample ztest, here is the formula:
z = (sample mean  population mean)/(standard deviation divided by the square root of the sample size)
With your data:
z = (132.3  128)/(15/√50) = ?
Finish the calculation.
Check a ztable at 0.05 level of significance for a twotailed test.
If the ztest statistic exceeds the critical value from the ztable, reject the null. If the ztest statistic does not exceed the critical value from the ztable, do not reject the null.
I hope this will help get you started.