Social Studies 201 – Winter 2005

Problem Set 3

Due Friday, February 18, 2005

Note: No class on Friday, February 11.

1. Undergraduate students. Obtain the variance, standard deviation, and coefficient of relative variation for each of the variables, grade and time spent at community service, in Table 1. Explain, which of the two variables is most concentrated.

Table 1. Canadian undergraduate students, grades and community service, 2003

Discipline	Average grade on a seven-point scale	Average hours per week in community service, among those involved
Arts and Humanities	5.0	4.5
Biological Science	4.9	4.2
Business	4.6	4.3
Education	5.2	4.4
Engineering	4.6	3.8
Physical Science	4.7	3.4
Professional	5.2	5.4
Social Science	4.6	4.7

Source: Canada Undergraduate Survey Consortium, 2003 Graduating Students Survey. Tables 17 and 36. Available from University of Regina, Office of Resouce Planning, http://www.uregina.ca/presoff/orp/surveys.shtml

2. Alcohol consumption. Obtain the variance, standard deviation, and coefficient of relative variation of number of alcoholic drinks consumed per week for the low and high income individuals represented by the data in Table 2. In words, briefly compare the variability in alcohol consumption for the two groups.

Table 2. Frequency distributions of Saskatchewan respondents, classified by number of alcoholic drinks consumed per week, low and high personal income

Number of alcoholic drinks consumed per week	No. of respondents with income of:
	<$30,000	$30,000 plus
None	370	188
1-4	214	185
5-9	94	106
10-19	54	74
20-39	30	29
Total	762	582

Source: Adapted from Statistics Canada. Canadian Community Health Survey, cycle 1.2 [machine readable data file]. First Edition. Ottawa, ON: Statistics Canada [publisher and distributor] 6/21/2004.

3. Education level of Saskatchewan urban population. Table 3 gives the percentage distributions of years of education for Saskatchewan adults aged 25-64. Using the values of X specified in the second column, obtain the interquartile range and standard deviation for Saskatchewan adults living in each of the two urban areas. From these statistics and the distributions, write a sentence or two comparing the variability of the two groups.

Table 3. Percentage distribution of years of education completed for adults aged 25-64, large and small Saskatchewan cities, 2001

Education level of Saskatchewan adults		Percentage of adults
Highest level of education completed	Years completed (X)	Regina and Saskatoon	Other cities in Saskatchewan
Less than secondary	10	20	34
Completed secondary	12	23	21
Certificate/diploma	13	14	17
College	14	17	15
University	16	26	13
Total		100	100

Source: Census of Canada, 2001.

4. Explanations of probability. Explain which interpretation of probability (subjective, frequency, theoretical) is implied by the word in bold in each of the following quotes.

a. Referring to the United States, an article from The Globe and Mail, February 7, 2005 stated, “Already, the administration said it will request another $80-billion in the current fiscal year to finance military operations in Iraq and Afghanistan, so the 2004-05 deficit will likely set a new record.”

b. “The likelihood of obtaining exactly one head in four flips of an honest coin is 0.25.”

c. A Statistics Canada study about child care, released in The Daily on February 7, 2005, states “children in two working or studying parent households were more likely to be in someone else's home cared for by a non-relative.”

5. Computer file. Use the file SSAE98.SAV in the t:\public\students\201 folder for this question. Hand in the computer printout along with the written answers.

a. Use Analyze-Descriptive Statistics-Descriptives to obtain the mean and standard deviation for the four variables “admission standards too lax” to “lower tuition” in question 50 (UED1 to UED4) of the SSAE98 survey questionnaire. Also use Analyze-Descriptive Statistics-Frequencies to obtain the quartiles and histograms for these four variables. From the data on the printout, calculate the range, interquartile range, and coefficient of relative variation for each variable. Write a short note comparing the variability of the four variables, commenting particularly on how and why the variation for “lower tuition” differs from the variation for the other three variables.

b. Use Analyze-Compare Means-Means to obtain means and standard deviations for the four variables of part a. (UED1 to UED4), classified by (i) sex, and (ii) federal political preference (FV). Write a note describing and comparing the results from these two different sets of tables, contrasting how the means of some variables differ a lot by political preference, but how other variables are fairly similar across sex and across political preference.