3
Going up 7 and then down 4 can be represented by 7-4=3
Answer:
The value of the test statistic is of 0.22.
Step-by-step explanation:
Our test statistic is:

In which X is the sample mean,
is the expected mean,
is the standard deviation(square root of the variance) and n is the size of the sample.
A lumber company is making boards that are 2920.0 millimeters tall.
This means that
.
A sample of 12 is made, and it is found that they have a mean of 2922.7 millimeters with a variance of 121.00.
This means that
. So



The value of the test statistic is of 0.22.
You first work out the mean then for each number subtract the mean and square the result then work out the mean of those squared differences and take the square rot of that and you're done :)