Answer:
c) t-test of population mean
Explanation:
The t-test statistic is used in hypothesis testing. Here we would use a one sample t test to test our hypothesis. The one sample t test measures the statistical difference between the hypothesized mean and the sample mean. In a one sample t test or single sample t test, a test variable is measured against a test value.
Example we compare our test variable to the hypothesized mean value $75 above.
The t test is used instead of z score when standard deviation is unknown.
Using the t test, we either accept or reject the null hypothesis given alternative hypothesis.
1) 475
2)375
You need to multiply 25 by 27 and you get 675 then to get answer one you need to multiply 10 by 20 to get 200 the take 200 away from 675 to get 475 then do the same thing with the second problem 20x15 which is 300 the take 300 away from 675.
First make it that both denominators are the same.

Then add both numerators

Your final answer should be
Answer:
0.0384615385
Step-by-step explanation:
look at picture