Confidence Intervals and t-Tests

The video tutorial explains paired or dependent samples t-tests, including related samples, matched-pairs, and correlated samples t-tests. It covers the repeated measures t-test, commonly used to assess treatment effects on the same individuals, and the matched subjects design, which requires matching individuals across groups. The tutorial provides a detailed example of a repeated measures t-test, including hypothesis testing, calculating test statistics, and constructing confidence intervals. It emphasizes the importance of understanding the distribution of differences and making decisions based on statistical significance and confidence intervals.

What is another name for the paired samples t-test?

• Independent samples t-test

• Related samples t-test

• One-sample t-test

• Z-test

What is the primary use of a repeated measures t-test?

• To compare two different groups

• To examine the effect of a treatment on the same individuals

• To analyze categorical data

• To test for correlation

Which of the following is an advantage of the repeated measures t-test?

• Is less accurate

• Requires a smaller sample size

• Is more complex

• Requires a larger sample size

In a matched subjects design, how are individuals in one group paired with those in another?

• By age

• By gender

• Randomly

• Based on common attributes

What is required for the distribution of differences in a paired-samples t-test?

• It must be bimodal

• It must be skewed

• It must be approximately normal

• It must be uniform

What is the formula used to calculate the standard error of the mean of differences?

• Sum of differences divided by the number of pairs

• Standard deviation multiplied by the square root of the number of pairs

• Sum of squares of differences divided by the number of pairs

• Standard deviation divided by the square root of the number of pairs

What is the sum of squares of the differences in the example provided?

• 6

• 14

• 86

• 3.266

What is the mean of the sample differences in the example?

• 2.333

• 0.141

• 1.750

• 3.266

What is the standard deviation of the differences in the example?

• 3.266

• 2.333

• 1.750

• 0.141

What is the null hypothesis in a paired-samples t-test?

• The mean difference is not equal to zero

• The mean difference is greater than zero

• The mean difference is equal to zero

• The mean difference is less than zero