HTW2S-Proportions

Test the claim that p₁ = p₂. Use α = 0.05. The sample statistics listed below are from independent samples.

Sample statistics: n₁ = 50, x₁ = 35, and n₂ = 60, x₂ = 40

• There is enough evidence to reject the claim.

• There is not enough evidence to reject the claim.

• There is enough evidence to support the claim.

• There is not enough evidence to support the claim.

Test the claim that p₁ > p₂. Use α = 0.01. The sample statistics listed below are from independent samples.

Sample statistics: n₁ = 100, x₁ = 38, and n₂ = 140, x₂ = 50

• There is enough evidence to reject the claim.

• There is not enough evidence to reject the claim.

• There is enough evidence to support the claim.

• There is not enough evidence to support the claim.

A recent survey showed that in a sample of 100 elementary school teachers, 15 smoked. In a sample of 180 high school teachers, 36 smoked. Is the proportion of high school teachers who smoke greater than the proportion of elementary teachers who smoke? Use α = 0.01.

• There is enough evidence to reject the claim.

• There is not enough evidence to reject the claim.

• There is enough evidence to support the claim.

• There is not enough evidence to support the claim.

A random sample of 100 students at a high school was asked whether they would ask their father or mother for help with a homework assignment in science. A second sample of 100 different students was asked the same question for an assignment in history. If 43 students in the first sample and 47 students in the second sample replied that they turned to their mother rather than their father for help, test the claim whether the difference between the proportions is due to chance. Use α = 0.02.

• There is enough evidence to reject the claim.

• There is not enough evidence to reject the claim.

• There is enough evidence to support the claim.

• There is not enough evidence to support the claim.

In the initial test of the Salk vaccine for polio, 400,000 children were selected and divided into two groups of 200,000. One group was vaccinated with the Salk vaccine while the second group was vaccinated with a placebo. Of those vaccinated with the Salk vaccine, 33 later developed polio. Of those receiving the placebo, 115 later developed polio. Test the claim that the Salk vaccine is effective in lowering the polio rate. Use α = 0.01

• There is enough evidence to reject the claim.

• There is not enough evidence to reject the claim.

• There is enough evidence to support the claim.

• There is not enough evidence to support the claim.