Answer: 1.460
Step-by-step explanation:
Given : Researchers report that on average freshman who live on campus gain 15 pounds during their first year in college.
Let
represents the population mean .
Then, the set of hypothesis will be:-


We assume that this is normal distribution.
Sample size : n = 10, which is a small sample (n<30) ,s o we use t-test.
Sample mean : 
Standard deviation : 
The test statistic for population mean for small sample is given by :-


Hence , the value of test statistic = 1.460