Business Statistics - Week 11

Type II error is a false negative. (True/False)

True

The confidence coefficient is

is (1 - α)

If the confidence level is 95%, then what's the alpha coefficient?

0.05

If an interval estimate is said to be constructed at the 90% confidence level, the confidence coefficient would be

0.90

If the confidence level is at 90% then what's the Za/2 value?

1.645

A researcher can reject the null hypothesis if the p-value is less than the alpha value set up by the researcher. (True/False)

True

A sample size of 30 is small, but adequate if the distribution is normally distributed. (True/False)

True

The confidence level expressed as a decimal value is called the __________.

Confidence coefficient

A confidence interval for the population variance depends on the f distribution. (True/False)

False

A two-tail test should be utilized to determine whether there is evidence that the mean family income in the U.S. is greater than $30,000. (True/False)

False

In the steps of hypothesis testing, the critical value approach requires the following two steps: Step 4: Use the beta value to determine the p-value and the rejection rule. Step 5: Use the value of the critical value and the rejection rule to determine whether to accept the alternative hypothesis. (True/False)

False

Rejecting the null hypothesis in our sample when it is actually true in the population is called a Type II error. (True/False)

False

The standard deviation is always known in every single business problem. (True/False)

False

The GNC is currently under a state lawsuit in Oregon for "spiking" its dietary supplements. If you were a researcher wishing to determine whether GNC's claim that their dietary supplements contain no illegal synthetic drugs, is true or false. Then, what would be the alternative hypothesis of GNC's claim?

GNC does use illegal synthetic drugs

The null hypothesis is denoted by:

H0

The university believes by default that 35% or more of the entire student body attends school during the winter session break. If you were to test this claim from a researcher's standpoint, what would be the correct set of hypotheses to test this claim?

H0: P ≥ 0.35 H1: P < 0.35

The alternative hypothesis is denoted by:

H1

For a 95% confidence interval, the confidence coefficient is .95. (True/False)

True

If a researcher wishes to determine whether there is evidence that the alternative hypothesis claim that the mean family income in the U.S. is greater than $30,000 (Ha: > $30,000), then the researcher will need to conduct a ______ test.

One-tail

Power is the probability of correctly rejecting the null hypothesis when it is false. (True/False)

True

The critical value is the value that is compared with the test statistic to determine whether the null hypothesis should be rejected. (True/False)

True

When s is used to estimate the standard deviation, the margin of error is computed by using

The "t" test distribution for the mean

The probability of committing a Type I error when the null hypothesis is true is

The level of significance

A researcher can choose to use the critical value approach or the p-value approach to determine whether to accept, or reject the null hypothesis. (True/False)

True

The probability of making a Type II error is denoted by

β