Question

In: Statistics and Probability

To test whether extracurricular activity is a good predictor of college success, a college administrator records...

To test whether extracurricular activity is a good predictor of college success, a college administrator records whether students participated in extracurricular activities during high school and their subsequent college freshman GPA.

LEFT side of column: Activity RIGHT side: College GPA

(a). Code the dichotomous variable and then compute a point-biserial correlation coefficient. (Round your answer to three decimal places.)

Yes 3.54
Yes 3.28
Yes 3.96
Yes 3.71
No 3.00
No 3.82
No 3.43
No 2.79
No 3.89
No 2.75

Solutions

Expert Solution

The dichotomous variable Y = whether students participated in extracurricular activities during high school is coded as shown below,

Now, the point-biserial correlation coefficient is obtained in excel by following these steps,

Step 1: Write the data values in excel

Step 2: Calculate the standard deviation for variable X using the function =STDEV(). The screenshot is shot is shown below,

Step 3: Separate the X value in separate column for each Y value and calculate the mean. The screenshot is shot is shown below,

Step 3: The point-biserial correlation coefficient is obtained using the formula,


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