Hypothesis Testing

Because we are interested in the average (as denoted by the use of x bar in the problem); we use the following z-score formula:

Z=\frac{\bar{X}-\mu}{\sigma/\sqrt{n}}

When using MS Excel—
Use NORM.DIST
input…

X = …
mean = 0
stndrd_dev = 1
cumulative = TRUE

output = 0.00135