Reference no: EM132856979
1. A college's job placement office collected data about students' GPAs and the salaries they earned in their first jobs after graduation. The mean GPA was 2.9 with a standard deviation of 0.4. Starting salaries had a mean of $47,200 with a Standard Deviation of $8,500. The correlation between the two variables was. The association appeared to be linear in the scatterplot.
a) The equation of the model that can predict salary (y) based on GPA (x) is
b) How much of the variability in salary is explained by GPA?
c) Your brother just graduated from that college with a GPA of 3.30. He tells you that based on this model the residual for his pay is. What salary is he earning?
2. If the least-squares regression line for predicting y from x is, what is the predicted value of y when x = 10? Explain.
A. 300 B. 500 C. 4800 D. 700 E. 20
3. Suppose that the least-squares regression line for predicting y from x is. Which of the following is a possible value for the correlation between x and y? Explain.
A. 1.3 B. -1.3 C. 0 D. -0.5 E. 0.5
4. A study of the effects of television measured how many hours of television each of 125 the grade school children watched per week during a school year, and their reading scores. The study found that children who watch more television tend to have lower reading scores than children who watch fewer hours of television. The study report says that "Hours of television watched explained 9 percent of the observed variation in the reading scores of the 125 subjects." The correlation between hours of TV and reading score must be which of the following? Explain.
A. B. C. D. E. It's impossible to tell from the information given
5. Explain why 5% of all relationships that occur by chance alone will erroneously earn the title of being 'statistically significant.'
6. Determine whether or not the following statement could be statistically correct. If not, explain why not. "The correlation between tree diameter and weight of fruit harvested was found to be 2.3."
7. Determine whether or not the following statement could be statistically correct. If not, explain why not. "The correlation between tree diameter and tree height in feet is .69. In yards, this correlation would become .69/3 = .23."