University of Phoenix Material
Week Two Practice Problems
Prepare a written response to the following questions.
12. For the following scores, find the mean, median, sum of squared deviations, variance, and standard deviation:
1,112; 1,245; 1,361; 1,372; 1,472
Sum of squared deviation: 76,089.2
Standard deviation: 123.36
16. A psychologist interested in political behavior measured the square footage of the desks in the official office for four U.S. governors and of four chief executive officers (CEOs) of major U.S. corporations. The figures ...view middle of the document...
The last step is to find the variance of 35. This is done by finding the square root of the variance. The answer will be the standard deviation. For the governor’s chairs the standard deviation is 5.91.
c. Note the ways in which the means and standard deviations differ, and speculate on the possible meaning of these differences, presuming that they are representative of U.S. governors and large corporations’ CEOs in general.
The means are very close, governor’s 43 and CEO’s 44. This shows that the averages of the different sized desks, though similar, are still different averages. This also indicates that, on the average, CEO’s have larger desks and it will show great differences in the standard deviation. The standard deviation between the two is quite different, governor’s 5.92 and CEO’s 10.95. This means that there is a higher deviation in desk sizes for the CEO’s than for the governors. This means that the CEO’s desks sizes fall closer to the mean (average) than those of the governor’s.
21. Radel and colleagues (2011) conducted a study of how feeling overly controlled makes you desire—even unconsciously—more freedom. In their study, 52 Canadian undergraduates played a video game in a laboratory and were randomly assigned to either:
a. an autonomy deprivation condition, in which they were told to follow instructions precisely, constantly given instructions over a loudspeaker, and carefully observed on everything they did.
b. a neutral condition, which was much more laid back.
After this activity, they were asked to do a “lexical decision task” (a standard approach for measuring unconscious responses) in which they were shown a series of words and nonwords in random order and had to press “C” if it was a real word or “N” if not. Half of the real words were related to autonomy (e.g., freedom, choice) and half were neutral (e.g., whisper, hammer). The key focus of the study was on how long it took people to press the button *(“response latency”) for each kind of real word, averaged over the many words of each type. The table below shows the mean and standard deviation across the participants of these four categories of results. Thus, for example, 782 milliseconds (thousandths of a second) is the average time it took participants in the autonomy-deprived condition to respond to the autonomy-related words, and 211 is the standard deviation across the 26 participants’ average response time in that condition. Explain the numbers in this table to a person who has never had a course in statistics. (Be sure to explain some specific numbers, as well as the general principle of the mean and standard deviation.) For your interest, the pattern of results shown here supported the researchers’ hypothesis: “Relative to a neutral instructional climate, a controlling climate thwarting the need for autonomy…enhanced accessibility for autonomy-related words.” (p.924).
Mean Latencies (in Milliseconds) in the Lexical Task...