Question

For the following questions , identify the type of test that should be used. Simply use the corresponding letter: A) One-sample z test (for a mean); B) One-sample t-test; C) One-sample z-test for a proportion (or a chi-squared goodness-of-fit); D) Chi-square goodness of fit (and a z-test is not appropriate); E) Two-sample z-test for a difference between proportions (or a chi-squared test for independence); F) Chi-square test for independence (and a z-test is not appropriate); G) Simple regression; H) Multiple regression; I) Two-independent samples t-test (with homogeneity of variance); J) Two-independent samples t-test (without homogeneity of variance);       K) Two-related samples t-test; L) One-way (independent measures) ANOVA; M) One-way Repeated measures ANOVA; N) Two-way ANOVA (independent, mixed, or repeated measures); O) Mann-Whitney; P) Wilcoxon; Q) Kruskal-Wallis; R) Friedman; If you are going down the interval/ratio branch, it is safe to use parametric measures, unless something is directly stated that clearly indicates otherwise, or unless the data strongly and unambiguously indicates otherwise. Similarly, it is safe to assume homogeneity of variance unless it is clearly indicated otherwise. Do not try to analyze whether or not the experiment is tenable or practical or flawless. This is not your concern right now. Most of the below were written by students in this class.

4.         The manager of a grocery store selected a random sample of 14 customers to investigate the association between the number of customers in a checkout line and the time it takes to checkout. As soon as the selected customer entered the end of the line, data was collected on the number of customers in the line in front of the selected customer and the time, in seconds, until they finished checkout. This store can get very crowded and there can be up to twenty customers in a line.

5.         Thomas wants to find out if California bees prefer red or yellow flowers. He sets up a camera that faces both a red and a yellow flower. (The red and yellow flowers are next to each other.) He then counts the number of bees that visit the red flower and the number of bees that visit the yellow flower. He has multiple cameras set up throughout California. Thomas does not feel comfortable making parametric assumptions. [Note to the student who wrote this: Obviously I changed your question a little bit, which changes the answer.]

6.         While grading essays, a TA noticed that students who hand-wrote the essay seemed to do worse than those who typed it. The TA also feels that this hypothesis mainly affects female students. She wants to check this, too; thus, she notes if the essay were written by a male or a female. The dependent variable is total point score on the essay and can be assumed to be interval in nature.

Answer 1

4.

We are interested in the association between the number of customers in a checkout line (independent variable) and the time it takes to checkout (dependent variable).  There can be up to twenty customers in a line, so the independent variable x ranges from 0 to 20. To test for the association between these two variables, Simple regression (G) test can be used. The significance test of the slope coefficient of the estimated regression will test for the association.

5.

For non-parametric assumptions, the difference between two independent populations (bees visiting the red flower and yellow flower), can be tested by O) Mann-Whitney Test

6.

We need to determine whether there is significant differences in mean point score based on factors - Essay - Handwritten or Typed and Gender. Since the assumption of homogeneity of variance is satisfied and there are two factors, we will use  N) Two-way ANOVA (independent) test.