1) Which of the following would require a paired t-test?

a) You wish to test whether eyebrow bushiness is greater among people born and raised in steel manufacturing towns compared to those born in non-steel manufacturing towns, examining one person from each town across 20 towns (10 steel producing, and 10 non-steel producing

b) You wish to determine whether the height of plant species A is greater in fertilized vs. unfertilized plots, examining one play per plot from 70 randomly chosen plots (35 fertilized and 35 unfertilized

c) You wish to test whether leopard frogs can jump farther than green frogs, testing 40 randomly selected frogs from each species

d) You wish to determine whether the pinky finger or thumb are longer, examining 30 randomly chosen people

2) A researcher is interested in testing whether fertilizer leads to increased plant growth for a species that typically grows under low nutrients. She does not have much growth chamber space, so she first grows the plants from the fertilized treatment in the chamber, and then after those are harvested, grows the control plants without fertilizer in the same chamber. She used 15 plants for each treatment, and shuffled them around spatially in the growth chamber every week. One way this design could have been improved to reduce bias would have been:

a) Buying another growth chamber so the control plants can be grown at the same time

b) Increasing the fertilizer levels in the fertilization treatment

c) Increasing the sample size

d) Growing half of the control and half of the fertilized plants in each time period

3) You wish to conduct an ANOVA to determine whether the attractiveness of men with mustaches varies across three height categories.You collect data on mustache attractiveness (numerical scale) for 50 individuals in each group. The distributions are positively skewed for each height category, and this cannot be resolved by transforming the data. What test do you use?

a) Kruskall-Wallis test

b) Mann-Whitney U test

c) Sign test

d) ANOVA

4) You test the effects of having low, medium, and high light on the speed of hair loss. Which of the following best describes this experimental scenario?

a) A Random effect

b) Both a fixed and random effect

c) A Fixed effect

d) Neither a fixed nor a random effect

5) Correlation coefficients represent:

a) The tendency of two variables to increase together

b) The tendency for two variables to vary together

c) The tendency of two variables to decrease together

d) The tendency for two variables not to vary together

6) What is the slope for the following graph? (no fractions please)

b. 3 2 0 0 2 3 X