Question 1: Suppose that you want to test the effect of salinity on crop growth. You have 20 available plants of the same species and variety. You randomly select 10 plants and use saline (15 ppt) water to grow these plants. Other plants are given fresh water. All other conditions are maintained the same. After 30 days, all plants are harvested and the mean biomass of the two groups are compared.

This is an example of:

• two independent samples or
• matched / paired samples

Question 2: Suppose that you want to test the effectiveness of a new K-12 environmental education program. The goal of the program is to improve children's interest in environmental issues. There are 20 children participating in the study. They took a pre-survey which asks their level of interest in various environmental issues. After they completed the program, they took the same survey. Their pre-survey and post-survey scores are compared.

This is an example of

• two independent samples or
• matched / paired samples

Question 3: Suppose that you want to compare the mean values of two independent groups (group 1 and group 2). Your hypothesis is whether the two mean values are different.

Select the correct hypothesis.

• H0: 1<2, Ha: 1>2
• H0: 1>2, Ha: 1<2
• H0: 1=2, Ha: 12
• H0: 12, Ha: 1=2

Question 4: Suppose that you want to compare the mean values of two independent groups (group 1 and group 2). Your hypothesis is whether the mean of group 1 is smaller than the mean of group 2.

Select the correct hypothesis.

• H0: 1=2, Ha: 12
• H0: 12, Ha: 1=2
• H0: 12, Ha: 1<2
• H0: 1>2, Ha: 1<2

Question 5 : In testing a hypothesis about population mean, if you know the population standard deviation, you can use:

• uniform distribution.
• the binomial distribution.
• the Student's t-distribution.
• the normal distribution.

Question 6: Let x be a hypothesized mean value. Select an appropriate type of hypothesis for the following:H0: = x, Ha: > x

• Two tailed test
• Upper (or right) tailed test
• Lower (or left) tailed test
• Lower (or right) tailed

Question 7: Let x be a hypothesized mean value. Select an appropriate type of hypothesis for the following: H0: = x, Ha: < x

• Upper (or right) tailed test
• Two tailed test
• Upper (or left) tailed test
• Lower (or left) tailed test

Question 8: If p-value > , then:

• we do not reject the H0. There is significant evidence to support Ha.
• we reject the H0. There is not significant evidence to support Ha.
• we reject the H0. There is significant evidence to support Ha.
• we do not reject the H0. There is not significant evidence to support Ha.

Question 9: Type I error is an error in hypothesis testing in which:

• a false null hypothesis is not rejected.
• a true null hypothesis is rejected.
• a true null hypothesis is not rejected.
• a false null hypothesis is not rejected.

Question 10: "The results of the data are not significant" implies:

• there is sufficient evidence to support Ha at the -level.
• there is sufficient evidence to support H0 at the -level.
• there is insufficient evidence to support Ha at the -level.
• there is insufficient evidence to support H0 at the -level.

Question 11: The hypothesis that a researcher tries to prove is called:

• the alternative hypothesis
• the null hypothesis
• the alternate hypothesis
• the initial hypothesis

Question 12: The symbol stands for:

• the significance level in a hypothesis testing and it is equivalent to the type II error rate.
• the significance level in a hypothesis testing and it is equivalent to the type I error rate.
• p-value in a hypothesis testing and it is equivalent to the type I error rate.
• p-value in a hypothesis testing and it is equivalent to the type II error rate.

Question 13: The hypothesis, H0: 1=2, Ha: 12, is an example of:

• two tailed test.
• upper (right) tailed test.
• paired test.
• lower (left) tailed test.

Question 14: The hypothesis, H0: 1=2, Ha: 1>2, is an example of:

• lower (left) tailed test.
• upper (right) tailed test.
• two tailed test.
• paired test.

Question 15: Suppose that you test a hypothesis whether the population mean values of two independent groups (group 1 and group 2) are different. You use = 0.01 and the p-value is 0.05. This result implies that:

• this hypothesis testing is inconclusive.
• this hypothesis testing is invalid.
• the mean values of the two groups are not significantly different at = 0.01.
• the mean values of the two groups are significantly different at = 0.01.