Correlation and Regression Assignment A sample of 10 adult men gave the followin
ID: 3157231 • Letter: C
Question
Correlation and Regression Assignment A sample of 10 adult men gave the following data on their heights and weights. Height (inches) X 62 62 63 65 66 67 68 68 70 72 Weight (pounds) Y 120 140 130 150 142 130 135 175 149 168 -Predict the weight of a man whose height is 60 inches. - Find a 90% confidence interval for men of height 60 inches (use your answer from part g). Include your interpretation of the confidence interval. Show your formula for E with all important values included. - Predict the height of a man whose weight is 160 pounds.
Explanation / Answer
XY and X2 as it was done in the table below.
the sum of every column:
X=663 , Y=1439 , XY=95748 , X2=44059
using the formula for a and b
we will get a = -78.37
b = 3.35
y = -78.37 +3.35x
we need to find weight at height 60
y = -78.37 +3.35*60
y = 122.63
now we need to find the height for weight 160
160 = -78.37 +3.35x
x = 238/37/3.35
x = 71.15
XY , X2 and Y2 as it was done in the table below.
the sum of every column to get:
X=663 , Y=1439 , XY=95748 , X2=44059 , Y2=209739
Use the following formula to work out the correlation coefficient.
r = 0.656
X Y XY XX 62 120 7440 3844 62 140 8680 3844 63 130 8190 3969 65 150 9750 4225 66 142 9372 4356 67 130 8710 4489 68 135 9180 4624 68 175 11900 4624 70 149 10430 4900 72 168 12096 5184