A “quick” step backwards

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Presentation transcript:

A “quick” step backwards

Blanched Formula Good way to calculate r if the means and standard deviations are already provided. It is very time consuming to calculate these statistics if they are not already provided If means and standard deviations are not given, use the raw-score formula

Raw-Score Formula r =

Step 1: Set up table

Step 2: Square Y

Step 3: Square X

Step 4: Multiply XY

Step 5: Sum

Step 6: Plug in values r = Y = 23 Y2 = 135 X = 15 X2 = 55 XY = 84 N = 5

Step 6: Plug in values r = Y = 23 Y2 = 135 X = 15 X2 = 55 XY = 84 N = 5

Step 6: Plug in values r = Y = 23 Y2 = 135 X = 15 X2 = 55 XY = 84 N = 5

Step 6: Plug in values r = Y = 23 Y2 = 135 X = 15 X2 = 55 84 15 23 r = 15 23 Y = 23 Y2 = 135 X = 15 X2 = 55 XY = 84 N = 5

Step 6: Plug in values r = Y = 23 Y2 = 135 X = 15 X2 = 55 84 15 23 r = 55 15 23 Y = 23 Y2 = 135 X = 15 X2 = 55 XY = 84 N = 5

Step 6: Plug in values r = Y = 23 Y2 = 135 X = 15 X2 = 55 84 15 23 r = 55 135 15 23 Y = 23 Y2 = 135 X = 15 X2 = 55 XY = 84 N = 5

Step 6: Plug in values r = Y = 23 Y2 = 135 X = 15 X2 = 55 (5) 84 15 23 r = (5) 55 (5) 135 15 23 Y = 23 Y2 = 135 X = 15 X2 = 55 XY = 84 N = 5

Step 7: Solve! r = Y = 23 Y2 = 135 X = 15 X2 = 55 XY = 84 N = 5 (5) 84 15 23 r = (5) 55 (5) 135 15 23 Y = 23 Y2 = 135 X = 15 X2 = 55 XY = 84 N = 5

Step 7: Solve! r = Y = 23 Y2 = 135 X = 15 X2 = 55 XY = 84 N = 5 (5) 84 15 23 r = (5) 55 (5) 135 23 225 529 225 Y = 23 Y2 = 135 X = 15 X2 = 55 XY = 84 N = 5

Step 7: Solve! r = Y = 23 Y2 = 135 X = 15 X2 = 55 XY = 84 N = 5 420 345 23 23 15 r = 275 23 225 675 529 225 Y = 23 Y2 = 135 X = 15 X2 = 55 XY = 84 N = 5

Step 7: Solve! r = Y = 23 Y2 = 135 X = 15 X2 = 55 XY = 84 N = 5 420 345 23 23 15 r = 50 23 146 225 Y = 23 Y2 = 135 X = 15 X2 = 55 XY = 84 N = 5

Step 7: Solve! r = Y = 23 Y2 = 135 X = 15 X2 = 55 XY = 84 N = 5 75 23 23 15 r = 146 23 7300 50 225 Y = 23 Y2 = 135 X = 15 X2 = 55 XY = 84 N = 5

Step 7: Solve! r = Y = 23 Y2 = 135 X = 15 X2 = 55 XY = 84 N = 5 75 23 23 15 r = 85.44 146 23 7300 50 225 Y = 23 Y2 = 135 X = 15 X2 = 55 XY = 84 N = 5

Step 7: Solve! .88 = Y = 23 Y2 = 135 X = 15 X2 = 55 XY = 84 N = 5 75 23 23 15 .88 = 85.44 146 23 7300 50 225 Y = 23 Y2 = 135 X = 15 X2 = 55 XY = 84 N = 5

Practice

Practice

Practice

Practice r = X = 20 X2 = 120 Y = 19 Y2 = 123 XY = 72 N = 4 (4) 72

Practice r = X = 20 X2 = 120 Y = 19 Y2 = 123 XY = 72 N = 4 -92 20 (4) 120 (4) 123 20 19 X = 20 X2 = 120 Y = 19 Y2 = 123 XY = 72 N = 4

Practice r = X = 20 X2 = 120 Y = 19 Y2 = 123 XY = 72 N = 4 -92 20 80 131 X = 20 X2 = 120 Y = 19 Y2 = 123 XY = 72 N = 4

Practice -.90 = X = 20 X2 = 120 Y = 19 Y2 = 123 XY = 72 N = 4 -92 102.37 80 131 X = 20 X2 = 120 Y = 19 Y2 = 123 XY = 72 N = 4

Practice Page 116 -- # 21

Practice Interpret the following: 1) The correlation between vocational-interest scores at age 20 and at age 40 was .70. 2) Age and IQ is correlated -.16. 3) The correlation between IQ and family size is -.30. 4) The correlation between sexual promiscuity and dominance is .32. 5) In a sample of males happiness and height is correlated .11.

Practice Page 97 # 5