Atextbook company states that the average time a student needs to take a quiz from its book is 30 minutes with a standard deviation of 3 minutes. a teacher using the book is not sure that this is correct for her classes and wants to check. she collects data on 10 random students and finds that the average time to take the quiz was only 25 minutes. as a result, the teacher performs a two-tailed hypothesis test with a significance level of 5%. which conclusion is valid based on the results of the test?

We accept the alternate hypothesis and the teacher was correct in claiming that the mean time to attempt quiz is not 30 minutes. Step-by-step explanation:

We are given the following in the question:

Population mean, μ = 30 minutes

Sample mean, = 25 minutes

Sample size, n = 10

Alpha, α = 0.05

Population standard deviation, σ = 3 minutes

First, we design the null and the alternate hypothesis

We use Two-tailed t test to perform this hypothesis.

Formula:

Putting all the values, we have

Now,

Since,  

We reject the null hypothesis and fail to accept it.

We accept the alternate hypothesis and the teacher was correct in claiming that the mean time to attempt quiz is not 30 minutes.

step-by-step explanation:

answer: what are the following choices