STAT250_WEEK3

Which one of the following hypothesis cannot be a null hypothesis?

• H₀ : μ = 100

• H₀ : σ² ≥ 25

• H₀ : s = 10

• H₀ : p < 8

Suppose that someone collects data from 15 articles. Assume that data follow a normal distribution, and the population variance is unknown. Then the test statistic is

• Z-test

• t-test

• Z-test or t-test

• We cannot use any test

• F-test

If you reject the null hypothesis when it is false, then you have committed:

• a type II error

• a type I error

• no error

• type I and type II error

The larger the p-value, the more likely you are to reject the null hypothesis.

• TRUE

• FALSE

Type I error is also called

• alpha

• beta

• p-value

• 1-beta

• critical value error

A type II error is committed when:

• you reject a null hypothesis that is true

• you don’t reject a null hypothesis that is true

• you reject a null hypothesis that is false

• you don’t reject a null hypothesis that is false

If p-value > alpha , we reject the null hypothesis.

• TRUE

• FALSE

Consider doing a hypothesis test on population mean. When the population variance is known and we have small sample size, the distribution of the test statistic is _________  .

• Z test

• t test

• Z test or t test

• We cannat use any test

• F-test

In their advertisements, a new diet program would like to claim that their methods result in a mean weight loss of more than ten pounds in two weeks. In order to determine if this is a valid claim, they hire an independent testing agency that then selects twenty-five people to be placed on this diet. The agency should be testing the null hypothesis H0: μ = 10 and the alternative hypothesis.

• H₁: μ < 10

• H₁: μ ≤ 10

• H₁: μ ≥ 10

• H₁: μ > 10

Let the calculated test statistic is 2.22 and the critical Z value is 2.34 for H₁: μ = 20 vs H₁: μ > 20. Then the decision is:

• Reject H₀

• Accept H₀

• Fail to reject H₀

• Fail to accept H₀

• We cannot decide