Homework

Part I - Multiple choice

1. A researcher is interested in whether more homework prompts higher tests scores. Which is the independent variable?
a. The test scores
b. Whatever prompts more homework
c. The researcher
d. Amount of homework

2. Which is accurate of qualitative variables?
a. The number indicates the amount of some characteristic
b. The variable has a constant value
c. The number indicates how high the quality is of some variable
d. The number is merely a label

3. If people are classified from the most, to the least creative, what is the measurement scale?
a. nominal
b. ordinal
c. interval
d. ratio

4. Percentile scores constitute data of what scale?
a. nominal
b. ordinal
c. interval
d. ratio

5. Data on the number of days absent indicate data of what scale?
a. nominal
b. ordinal
c. interval
d. ratio

6. Which statistic's value is unaffectedby one extreme outlier?
a. range
b. standard deviation
c. mean
d. mode

7. Which of the following is not a measure of data variability?
a. Range
b. Variance
c. Standard deviation
d. Mode

Items 8 - 11 refer to the following achievement scores: 23, 25, 28, 28, 28, 32, 32, 37, 42.

8. What is the value of the mean?
a. 19
b. 28
c. 30.556
d. 5.961

9. What is the value of the median?
a. 19
b. 28
c. 30.556
d. 5.961

10. What is the value of the mode?
a. 19
b. 28
c. 30.556
d. 5.961

11. What is the value of the range?
a. 19
b. 28
c. 30.556
d. 5.961

12. A bimodal distribution is created by which of the following?
a. Many low scores with values diminishing as they increase
b. Relatively few low scores and relatively few high scores
c. Scores which all have the same frequency
d. Many low scores, few medium scores and many high scores

Part II - SPSS data analysis and interpretation

This next set of questions will include the use of the SPSS data file temphr.sav. The N = 130 scores in this file are hypothetical data created by Shoemaker (1996) so that they yield results similar to those obtained in an actual study of temperature and heart rate (Machowiak et al., 1992).

Use the temperature data in the temphr.sav to do the following:

1. The variable "tempf" contains data measured in Fahrenheit and "tempc" measures temperature in centigrade. (NOTE: centigrade = (F - 32) / 1.8)

2. Find the mean, standard deviation, and standard error of the mean for both tempf and tempc. Provide a one sentence summary of the data for each variable noting any differences, if any, in their interpretability.

3. Examine a histogram of scores on tempc. Is the shape of the distribution reasonably close to normal?

4. The temperature that is popularly believed to be "average" or "healthy" is 98.6 F (37 C). How does this data look when compared to the average? From a practical standpoint, what conclusion might you draw from this result as it relates to the representativeness of this sample data to the population from which we are trying to generalize?

5. Find the mean, standard deviation and standard error of the mean for heart rate (HR). Describe, in words, the amount of variability in the data using the appropriate measure(s) of variance to support your explanation.

BONUS +1 point: This is not required, but give it a shot. This question will incent you to explore SPSS. You can only GAIN points for this question, there's nothing to lose.

Create a new variable called HRcat (heart rate categories). The variable should have 3 levels - low heart rate (for HR < 65), moderate (66 > 79) and high (> 80). Report the percentage of individuals that fall into each.