TABLE 13-9
It is believed that, the average numbers of hours spent studying per day (HOURS) during undergraduate education should have a positive linear relationship with the starting salary (SALARY, measured in thousands of dollars per month) after graduation. Given below is the Excel output for predicting starting salary (Y) using number of hours spent studying per day (X) for a sample of 51 students. NOTE: Only partial output is shown.

Note: 2.051E - 05 = 2.051*10⁻⁰⁵ and 5.944E - 18 = 5.944*10⁻¹⁸.
-Referring to Table 13-9, the estimated change in mean salary (in thousands of dollars) as a result of spending an extra hour per day studying is
A) -1.8940.
B) 0.7845.
C) 0.9795.
D) 335.0473.

Question

TABLE 13-9
It is believed that, the average numbers of hours spent studying per day (HOURS) during undergraduate education should have a positive linear relationship with the starting salary (SALARY, measured in thousands of dollars per month) after graduation. Given below is the Excel output for predicting starting salary (Y) using number of hours spent studying per day (X) for a sample of 51 students. NOTE: Only partial output is shown.
  
Note: 2.051E - 05 = 2.051*10⁻⁰⁵ and 5.944E - 18 = 5.944*10⁻¹⁸.
-Referring to Table 13-9, the estimated change in mean salary (in thousands of dollars) as a result of spending an extra hour per day studying is
A) -1.8940. 
B) 0.7845. 
C) 0.9795. 
D) 335.0473.

Quizplus · Accepted Answer

From the Excel output, we can see that the regression coefficient for HOURS is 0.9795. This means that, on average, for every additional hour spent studying per day, the starting salary is estimated to increase by 0.9795 thousand dollars (i.e., 979.5 dollars). Therefore, the estimated change in mean salary as a result of spending an extra hour per day studying is 0.9795.

TABLE 13-9 It Is Believed That, the Average Numbers of Hours Spent