Prob Stat Normal Distribution

A normal distribution has a mean of 61 and a standard deviation of 15. What is the median?

Mathematical Equivalence

ON

This data is normally distributed.  What percent of the data is in the shaded region?

• 68%

• 32%

• 95%

• 50%

(a)   , also known as the critical region, describes the entire area of values that indicates you reject the null hypothesis.

To determine the critical region if population variance is known, use table for _____________ distribution.

• z

• t

• chi

• table

Which of the following defines the area encompassed by the values not included in the non-rejection region or also the area of the tails of the distribution?

• critical value

• rejection region

• level of significance

• population variance

If the computed z-value is 1.915 and the critical value is 1.812, which of the following statements could be true?

• It lies in the rejection region, 𝐻𝑜 must be rejected.

• It lies in the rejection region, hence we fail to reject𝐻𝑜.

• It lies in the non-rejection region, 𝐻𝑜 must be rejected.

• It lies in the non-rejection region, hence we fail to reject𝐻�

What term is being used to describe a proposed explanation, assertion, or assumption about a population parameter or about the distribution of a random variable?

• statistic

• decision

• hypothesis

• probability

If the computed z-value is 1.286 and the critical value is 1.383, which of the following statements could be true?

• It lies in the rejection region, 𝐻𝑜 must be rejected.

• It lies in the non-rejection region, hence we fail to reject 𝐻𝑜.

• We fail to reject a null hypothesis that is true.

• We fail to reject a null hypothesis that is false.

Using a left-tailed test, which of the following value of z will not fall in the rejection region where the critical value is – 1.638?

• – 1.637

• – 1.639

• – 1.641

• – 1.706

Which of the following describes an alternative hypothesis using two-tailed test?

• 𝐻𝑎: 𝜇 < 50 𝑦𝑒𝑎𝑟𝑠 𝑜𝑙𝑑

• 𝐻𝑎: 𝜇 ≠ 50 𝑦𝑒𝑎𝑟𝑠 𝑜𝑙𝑑

• 𝐻𝑎: 𝜇 > 50 𝑦𝑒𝑎𝑟𝑠 𝑜𝑙𝑑

• 𝐻𝑎: 𝜇 = 50 𝑦𝑒𝑎𝑟𝑠 𝑜𝑙𝑑