A study was conducted to compare the average time spent in the lab each week versus course grade for computer students.The results are recorded in the table below. Number of hours spent in lab Grade (percent)
10 96
11 51
16 62
9 58
7 89
15 81
16 46
10 51
A)-0.284
B)-0.335
C)0.371
D)0.462
E)0.017

Question

Quizplus · Accepted Answer

To find the correlation coefficient between time spent in the lab and course grade, we first need to calculate the mean, standard deviation, and covariance for both variables. Using a calculator or software, we get:

Mean of time spent in lab: 11.375
Standard deviation of time spent in lab: 3.494
Mean of course grade: 67.286
Standard deviation of course grade: 19.079
Covariance: -68.696

Then, we can use the formula for correlation coefficient:

r = Covariance / (Standard deviation of time spent in lab * Standard deviation of course grade)

Plugging in the values, we get:

r = -68.696 / (3.494 * 19.079) = -0.3349

Rounding to three decimal places, the correlation coefficient is approximately -0.335, which corresponds to choice B as the answer. This indicates a moderate negative correlation between time spent in the lab and course grade.

A Study Was Conducted to Compare the Average Time Spent