Section 4 Extra Credit Quiz

The null hypothesis

Both “Is a statement about the value of the population parameter” and “Will always contain the equal sign” are correct.

The level of significance

All of the above.

The critical value is

The point that divides the acceptance region from the rejection region.

In a one-tailed test

The rejection region is in only one of the tails.

To conduct a one sample test of means and use the z distribution as the test statistic

Both “We need to know the population mean” and “We need to know the population standard deviation” are correct.

For a one-tailed test using the 0.05 level of significance, the critical value for the z test is 1.645, but for t it is 1.96.

False

When the population standard deviation is unknown and the sample size n<30, the test statistic is the Student's t distribution.

True

What is the critical value for a one-tailed hypothesis test in which a null hypothesis is tested at the 5% level of significance based on a sample size of 25?

1.711

If the 1% level of significance is used and the computed value of z is +6.00, what is our decision?

Reject H₀

What are the critical z-values for a two-tailed hypothesis test if a = 0.01?

± 2.58

What is the critical value for a one-tailed hypothesis test in which a null hypothesis is tested at the 5% level of significance based on a sample size of 25?

1.711

If the 1% level of significance is used for a one tailed test seeking to prove that the mean μ is > 30 and the computed value of z is +6.00) what is our decision?

Reject H₀

What are the critical z-values for a two-tailed hypothesis test if a = 0.01?

± 2.58

If the null hypothesis states that there is no difference between the mean income of males and the mean income of females, then the test is one-tailed.

False

If we are testing for the difference between two population proportions, it is assumed that the two populations are approximately normal and have equal variances.

False

When sample sizes are less than 30, a test for the differences between two population means has n-1 degrees of freedom.

False

We use the pooled estimate of the proportion in testing the difference between two population proportions.

True

If the decision is to reject the null hypothesis of no difference between two population parameters, at the 5% level of significance, what are examples of the alternate hypothesis and rejection region?

𝜋₁ ≠ 𝜋₂; 𝗓﹥1.96 and z﹤-1.96

If the null hypothesis that two means are equal is true, where will 97% of the computed z-values lie between?

± 2.17

Administering the same test to a group of 15 students and a second group of 15 students to see which group has a higher average score is an example of

a two sample test of means.

Tested at the 5% level of significance based on two samples, both sample sizes are 13? Assume the population standard deviations are equal.

1.711