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# Confidence Interval

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It has been determined that the correlation between a very good predictor variable and college GPA is .69. Also, the standard error of the estimate is .54 based on the four point grading scale. If a student should expect a 2.75 GPA, what are the 95% expectations for the student?

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https://brainmass.com/statistics/confidence-interval/confidence-interval-expected-values-18652

## SOLUTION This solution is FREE courtesy of BrainMass!

standard error of estimate =Se = 0.54

Assuming sample size is large we will use normal distribution

Confidence interval= 95%

Z value for 95% confidence interval= 1.96

Y (est)= 2.75

Upper limit= Y (est)+z*Se= 3.81 =2.75+1.96*0.54

Lower limit= Y (est)-z*Se= 1.69 =2.75-1.96*0.54

Answer: The GPA would lie between 1.69 and 3.81 for 95% confidence

This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

Â© BrainMass Inc. brainmass.com December 24, 2021, 4:57 pm ad1c9bdddf>
https://brainmass.com/statistics/confidence-interval/confidence-interval-expected-values-18652