Question

As the sample size used to obtain a confidence interval increases, the margin of error

Select one:

a. increases.

b. remains constant.

c. none of these.

d. decreases.

In 2008, 62% of American adults regularly volunteered their time for charity work. A researcher believes that this percentage is different today.

Select one:

a. all of these are true.

b. the alternative hypothesis is: p = 0.62

c. the null hypothesis is H₀: p≠0.62.

d. the alternative is a two-tailed hypothesis

In hypothesis testing, the alternative hypothesis is

Select one:

a. a tentative assumption about a sample mean.

b. a tentative assumption about a population parameter.

c. an evidence in support of the null hypothesis.

d. a statement that is the opposite of what is stated in the null hypothesis.

Which best describes the lower endpoint of a confidence interval?

Select one:

a. point estimate minus margin of error

b. none of these is true.

c. point estimate plus margin of error

d. point estimate

Answer 1

1. As the sample size increases in a given confidence interval where population mean is estimated to lie in the interval of sample mean margin error which is critical t value times standard error as standard error decreases with increase in n hence margin error also lessens.

The correct option is d

2. The claim is that p=0.62 hence it will be null hypothesis and research would test it with an alternative p not equal to 0.62 which is required to be proved. It is a two tailed hypothesis

The correct option is d

3. In a hypothesis, alternative hypothesis is a statement which is opposite of what the null hypothesis asserts.

The correct option is d

4. The lower end point of a confidence interval is the point estimate minus margin error

The correct option is a