A score of 243 is a "basic" reading level.

Question

Scores for a random sample of 3000 students had a xbar = 250 with a standard error 1.0
The 99% confidence interval for the mean score all students in the city is 247.4 to 252.6.

Ques: Is there good evidence that the mean for all students in the city is less than the basic level?

Ans: 243 is not in the 99% confidence level. It is below.
The answer in the back of the book says:"we would fail to reject Ho: u=243 against the one-sided alternative hypothesis Ha: u (less than) 243 at the 1% significance level."

I do not understand the book answer "we would fail to reject..."

Does this mean there IS good evidence that the mean is less than the basic level? or NOT?

Answer 1

Ho: µ = 243
Ha: µ < 243

I would definitely reject Ha. But since we have only two hypotheses, that would leave me to "fail to reject" Ho. However, I would rather accept Ha: µ > 243, but that was not an included hypothesis.