The sample mean is 12 for a sample of 26. The sample deviation is 3. Use the .02 level of significance
The following information is available.
H0: ≤ 10
H1: > 10
Try a t-test since your sample size is rather small.
Formula:
t = (sample mean - population mean)/(standard deviation divided by the square root of the sample size)
sample mean = 12
population mean = 10
standard deviation = 3
sample size = 26
Plug in the values and calculate the t-test statistic.
Find the critical value for a one-tailed test at .02 level of significance using 25 for degrees of freedom (df = n - 1). Use a t-table. Compare to your t-test statistic calculated above. If the t-test statistic exceeds the critical value from the table, reject the null. If the t-test statistic does not exceed the critical value from the table, do not reject the null.
I hope this will help.