Add 31 to both sides which will give you
9h = 130
Answer:
The value of the test statistic is 
Step-by-step explanation:
The null hypothesis is:

The alternate hypotesis is:

Our test statistic is:

In which X is the sample mean,
is the null hypothesis value,
is the standard deviation and n is the size of the sample.
In this problem:

So



The value of the test statistic is 
Answer:
20
Step-by-step explanation:
4:4,8,12,16,20
5,5,10,15,20
20 is the frist number u come to when multiplying by your 4s and 5s