Multiple Choice . Justify your Answers

1. A sample of 400 Regina households is selected and several variables are recorded. Which of the following statements is correct? a) Total household income (in $) is interval level data. b) Socioeconomic status (recorded as "low income", "middle income", or "high income" is nominal level data. c) The number of people living in a household is a discrete variable. d) The primary language spoken in the household is ordinal level data. e) None of the above. 2. What term would best describe the shape of the given boxplot: a) Symmetric b) Negatively Skewed c) Positively Skewed d) Uniform e) Normal 3. We have seen that outliers can produce problematic results. Rank the following measures in order or "least affected by outliers" to "most affected by outliers". a) mean, median, range b) median, mean, range c) range, median, mean d) median, range, mean e) range, mean, median4. Consider the result of a fictional Stat 100 final exam taken by 120 students, as given in the following relative frequency distribution: Grade Less than 50 50-59 60-69 70-79 80-89 90-100 Cumulative Frequency 15% 10% 30% 25% 15% 5% How many students received at least a 70 on this exam? a) 54 b) 45 c) 25 d) 30 9) 66 5. According to the empirical rule, approximately what percentage of normally distributed data lies within one standard deviation of the mean? a) 59% b) 68% c) 72% d) 95% e) 99.7% Note: Questions #6-#8 are based on the following sample of ages (in months) of 18 children at a day care: 36, 42, 18, 32, 22, 22, 25, 29, 30, 31, 19, 24, 35, 29, 26, 36, 24, 28 6. The median age of the children is... a) 29 b) 28.2 c) 30.5 d) 28.5 e) 31 7. The interquartile range for this data set is... 1) 8 b) 12 c) 16 d) 20 e) 24 8. The standard deviation of the age of children is... a) 41.24 b) 11.33 c) 10.20 d) 6.42 e) 6.24Note: Questions #9-#12 are based on the following grouped frequency table of the income, x 30 employees at a local small business (in $1000s). 3 / 11 Income $26