A random sample of 127 observations produced a sample mean of 30. Find the critical and observed values of z for the following test of hypothesis using α=0.01. The population standard deviation is...

A random sample of 127 observations produced a sample mean of 30. Find the critical and observed values ofz for the following test of hypothesis using α=0.01. The population standard deviation is known to be 8 and the population distribution is normal.

H0: μ=28 versus H1: μ>28.

Round your answers to two decimal places.

z
_critical =Enter your answer; z_critical

z
_observed =Enter your answer; z_observed