W1, W2, W3…W9 represent the holding times of 9 water samples, which follow a normal distribution with mean = 8.33 and standard deviation = 4.472.
M represents the sample mean value of holding times, which also has a normal distribution.
Assuming $Z$ has a standard normal distribution (mean = 0 and standard deviation = 1), select the correct statement which describes the expression for calculating the value of Type I error where:
\[
H_0: M>6 \text{(null hypothesis)}, H_a: M \leq 6 \text{(alternate hypothesis)}
\]