Hypothesis Testing

A single statement or a group of interconnected statement is called the null hypothesis.

• True

• False

The null hypothesis states that the sample observations are influenced by non-random causes.

• True

• False

Suppose that the present success rate in treating a certain type of lung cancer is .75. A research group hopes to demonstrate that the success rate of a new treatment of this cancer is better. What are the null and alternative hypotheses?

• H_o : p = 0.25, H_a : p > 0.55

• H_o : p < 0.75, H_a : p > 0.35

• H_o : p = 0.75, H_a : p > 0.75

• None of these.

At the Chrysler manufacturing plant, there is a part that is supposed to weigh precisely 19 pounds. The engineers take a sample of parts and want to know if they meet the weight specifications. What are our null and alternative hypotheses?

• H_o : μ = 17, H_a : μ ≠ 19

• H_o : μ = 19, H_a : μ ≠ 19

• H_o : μ = 19, H_a : μ ≠ 17

• H_o : μ = 17, H_a : μ ≠ 17

State the null hypothesis for the given alternative hypothesis: "The average dog owner owns more than two cats."

• The average dog owner owns two or more cats.

• The average dog owner owns less than two cats.

• The average dog owner owns two cats.

• None of the above.

Write the alternative hypothesis for the following question: H_o : p = 0.55 and the test is right sided.

• H_a : p > 0.55

• H_a : p < 0.55

• H_a : p ≤ 0.55

• H_a : p = 0.55

State the null hypothesis for the given alternative hypothesis: "The average computer gamer owns more than four games."

• The average computer gamer owns greater than four games.

• The average computer gamer owns four or fewer games.

• The average computer gamer owns four games.

• None of the above.

Write the alternative hypothesis for the following question: H_o : p = 0.35 and the test is left-sided.

• H_a : p > 0.35

• H_a : p ≤ 0.35

• H_a : p = 0.35

• H_a : p < 0.35

Use the notation to state the alternative hypothesis and null hypothesis: "Less than 4% of high school students take Statistics."

• H_o : X ≥ 4% and H₁ : X > 4%

• H_o : X ≤ 4% and H₁ : X < 4%

• H_o : X ≥ 4% and H₁ : X < 4%

• H_o : X > 4% and H₁ : X ≤ 4%

If the null hypothesis is false, then the sampling distribution of the chi square statistic can be closely approximated by a continuous curve known as a chi square distribution.

• False

• True