Midterm 2 review

Which of the following p-values suggests the highest level of significance?

• 0.012

• 0.14

• 0.011

• 0.15

Which of the following is a correct example of a significant result from a statistical test?

• The absolute value of the test statistic is lower than the critical value.

• You reject the null hypothesis.

• The p-value is higher than α

• You fail to accept the null hypothesis.

α is...

• A chosen threshold representing the probability of falsely rejecting the null.

• A statistically derived parameter representing the probability of falsely rejecting the null.

• A chosen threshold representing the probability of falsely failing to reject the null.

• A statistically derived parameter representing the probability of falsely failing to reject the null.

You decrease a sample size, this causes the 95% confidence interval to...

• Narrow

• Widen

• Stay the same

The 90% confidence interval for u1 is (-11.5 – 1.8). If we test H0: u1 = 2 and H1: u1 ≠ 2 with α = 0.05, can we reject the null hypothesis?

• Yes

• No

• Can't say from provided information

The 99% confidence interval for u1 is (10 – 28.1). If we test H0: u1 = 9.8 and H1: u1 ≠ 9.8 with α = 0.05, can we reject the null hypothesis?

• Yes

• No

• Can't say from provided information

Which of the follow are the correct interpretation of of a 95% CI: (15, 20)?

• 95% of values are between 15 and 20.

• We are 95% confident that the sample mean is between 15 and 20.

• We are 95% certain that the true population mean is between 15 and 20.

• If we sampled the same population again, we are 95% confident the new sample mean would be between 15 and 20.

We are studying the impacts of review session quality on midterm scores. We tested the same group of students with midterms of similar difficulty. For the midterm 1, we provided a high quality review session. For midterm 2, we provided a very poor review session. We scored the students after each midterm (S). We compared the difference in scores from each student under each review session condition (D) . We hypothesize that each student will have higher scores after the high quality review session. Which is the correct null and alternative hypothesis for this study?

• H0: S1 = S2

  H1: S1 ≠ S2

• H0: S1 = S2

  H1: S1 > S2

• H0: D = 0

  H1: D > 0

• H0: D = 0

  H1: D ≠ 0

We are studying the impacts of review session quality on midterm scores. We tested the same group of students with midterms of similar difficulty. For the midterm 1, we provided a high quality review session. For midterm 2, we provided a very poor review session. We scored the students after each midterm (S). We compared the difference in scores from each student under each review session condition (D). We hypothesize that each student will have higher scores after the high quality review session. Which is the correct statistical test to use in this study?

• One-tailed two-sample t-test

• One-tailed paired t-test

• Two-tailed paired t-test

• One-tailed one-sample t-test

Which of the follow statements are FALSE comparing binomial and poisson distributions?

• Both model binomial probabilities.

• Binomial has two parameters and poisson has one.

• Both are discrete probability distributions.

• Binomial models the number of events occurring, poisson does not.