Answer: the population has a mean of less than 30
Explanation:
In interval estimation, the t distribution is applicable only when a. the population has a mean of less than 30. the sample standard deviation (s) is given instead of the population standard deviation
Primary school is grades k-6 (or k-5 in some cases) and secondary school is grades 7-12 (or 6-12 in some cases).
C) national? I'm sorry if I am wrong
