Has a čláss with four recitation sections. Each section has 7 students (rare, but there are exactly the same number in each clas...how convenient for our purposes, yes?). At first glance, the professor has no reason to assume that these exam scores from the first test would not be independent and normally distributed with equal variance. However, the question is whether or not the section choice (different TAs and different days of the week) has any relationship with how students performed on the test. Group-1 Group-2 Group-3 Group-4 76.9 60.5 75.5 70.7 78.1 71.3 78.7 102.2 71.4 54.5 80.1 67.3 72.6 56.1 82.8 89.5 74.1 71.8 68.1 72.9 68.9 68.1 81.7 70.5 67.6 62.2 68.8 92.1

Solve the second one

Assume the mean and variance of 5 observations are 1 and 5, respectively. If 5, as one of these five observations, is removed, which of the followings gives the variance of the remaining observations? Select one: 2 1.25 0 None 0.75

. What are the values of SS and variance s? for the following sample of n=3 scores? Sample: 1, 4, 7

The mean and variance of a set of 9 observations have magnitudes 8 and 3 respectively. If two observations, of magnitude 9 and 7 are removed from the original set, then the magnitude of the new variance is approximately: A. 3.7 B. 3.8 C. 3.6 D. 3.5

and if the scores A set of 10 scores has SS= 90. If the scores are a sample, the sample variance is are a population, the population variance is O 2 - 10: ? = 10

The role of the covariate is to:     a.Compare variables of interest without a nuisance variable masking true differences. b.Reduce within-wroup error variance and help eliminate confounding variable bias. c.To determine the predictive power of the independent variable using odds d.A & B

For 20 consecutive weeks, a store owner recorded a sample number of customers each week as follows: 300 400 324 326 327 329 415 362 321 375392 383 345 391 395 400 362 396 420 430 Compute for the following:a. Medianb. Sample Variancec. Skewness Coefficient (Use Pearson’s Second Coefficient)

One of the great difficulties a small restaurant manager faces is to pleaseevery customer who differs widely in age. On a randomly selected evening, this restaurant served 12 customers whose ages reported below:        87 58 54 61 3 35 31 28 3 16 68 36   a) What are the mean, median, and mode of the data?   b) What measure of central tendency would you use here? Why?   c) Find the …ve-number summary of the data. ??

If two large random samples are drawn from two populations, each having a mean of $100, the relevant sampling distribution of their difference has a mean of a. 200 b. The Sum of the 2 Sample Means C. 0 D. The difference between the two sample means.