Exercises_on_Regression

# Exercises_on_Regression - (b John and Will score 485 and...

This preview shows pages 1–2. Sign up to view the full content.

February 3, 2010 Exercises on Regression and Prediction Multiple- Choice questions #1 The amount of regression toward the mean is least when r is a. low. b. high. c. negative. d. positive. #2 Which value of r permits the greatest accuracy of prediction? a. +.78 b. +.27 c. -.37 d. -.81 Fill- In Questions #1 The _________ reflects the angle and direction of the regression line. #2 The higher the correlation, the __________ the prediction error. #3 The ________________ is the one that minimizes the sum of the squares of the discrepancies between the actual value of Y and the predicted value.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Problems #1 The following data are for freshman students at Rochester University: APTITUDE SCOE: X FRESHMAN GPA: Y Mean of X = 560 Mean of Y = 2.65 SDx = 75 SDy = .35 r = +.50 (a) Write the regression equation for predicting Y from X.
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: (b) John and Will score 485 and 710, respectively, on the aptitude test. Predict the freshman GPA for each. (c) What assumption is necessary for this prediction to be valid? #2 A researcher was interested in the effect of stress level on the quality of marital interaction. She measured stress level and then observed the number of times a spouse spoke sharply during a two-hour test period, producing an irritability score. The fictional data from 4 participants are as follows: X Y Subject (Stress level) (Irritability) 1 4 10 2 10 15 3 2 7 4 6 7 Mx = 5.5 My = 9.75 Sx = 2.96 Sy = 3.27 r = 0.81 (a) Give the prediction formula for predicting the irritability from stress level (b) Predict the irritability level for someone with a stress level of 9...
View Full Document

{[ snackBarMessage ]}

### Page1 / 2

Exercises_on_Regression - (b John and Will score 485 and...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online