In an independent samples t-test, what concept does the numerator of the t-ratio measure?

A sample of 20 is selected from a population with an unknown mean. The one-sample t estimation equation is used to compute the 99% confidence interval around µ. Which of the values below should be used for t in this equation?  µ = 40 ± ( t )( 4 )

What does a z-score of -1.34 indicate for a score?

What would we expect to see in a positively skewed distribution?

What is the critical value for factor B in a Factorial ANOVA with N=77, 6 levels for factor A and 4 levels for factor B, and an alpha level of 0.05?

If I have a mean of 25 (ΣX= 100, n=4) and add another score of 25, what would the new mean equal?

A 99% confidence interval for the population mean ranges from 26 to 30. Based on this information:

What is the sum of squared deviations?   7, 4, 3, 2, 7, 1, 4

For a particular population a sample of n = 4 scores has an expected value of 10.  For the same population, a sample of n = 25 scores would have an expected value of ____.

A professor is using a new teaching method that is supposed to decrease his students’ exam scores. A one-tailed t-test was used. The critical value is 2.75 and the obtained value is 3.23. Which of the following is correct?