Question

It turns out that the life of a particular species of local tree is normally distributed with standard deviation of σ=3.2 years.   A sample mean of 26 years was calculated from a sample of 100 trees. Conduct a hypothesis test at the 0.01 level of significance to determine that the population mean is different from 25.

To conduct a hypothesis test, you must check conditions. Answer the below questions related to checking conditions:

Blank #1: Was the sample obtained in the right way? (yes or no)

Blank #2: Is the population Normal or if unknown, is the sample size large? (yes or no)

Blank #3: Is the population standard deviation known? (yes or no)

In addition, we always assume the null value is true as part of the test. If the answer to any of the above questions is no other than the first one, then just write NA in each of the following blanks. If the sample was not obtained in the right way, then for textbook problems in which we cannot carry on a conversation with the researcher to confirm, we will trust it and continue with the procedure.

So, by CLT, we can say the sample means from this population for sample size 100 are Normal with assumed mean _____________(blank #4) and standard deviation ____________________(blank #5)

Answer 1