1. A labor economist wants to know the relationship between education (measured by years of schooling) and annual earnings (measured in $1000). A random sample of 222 workers revealed a correction coefficient of 0.88. Based on the coefficient,
a. The slope of the scatter diagram (of education and earnings) equals to 0.88.
b. Earnings would increase by $880 for every year increase in education.
c. The more education, the higher annual earnings, and the relationship is close.
d. All of the above.
2. Among the measures of central tendency (mean, median, mode, quartiles), the most sensitive measure to extreme value(s) is
a. mean.
b. median.
c. mode.
d. quartiles.
3. The Pearson’s coefficient measures
a. the central tendency of a distribution.
b. the variability of a distribution.
c. the skewness of a distribution.
d. none of the above.
4. What is a disadvantage of the range as a measure of dispersion?
a. Based on only two observations
b. Can be distorted by a large mean
c. Not in the same units as the original data
d. Has no disadvantage
5. According to Chebyshev's Theorem, at least what percent of the observations lie within plus and minus 1.75 standard deviations of the mean?
a. 56%
b. 95%
c. 67%
d. Cannot compute because it depends on the shape of the distribution
6. A sample of the monthly amounts spent for food by families of four receiving food stamps approximates a symmetrical distribution. The sample mean is $150 and the standard deviation is $20. Using the Empirical Rule, about 95 percent of the monthly food expenditures are between what two amounts?
a. $100 and $200
b. $85 and $105
c. $205 and $220
d. $110 and $190