Physical therapists must often determine the ideal crutch length for their patie
ID: 3131504 • Letter: P
Question
Physical therapists must often determine the ideal crutch length for their patients. Many therapists use the patient’s self-reported height to arrive at this crutch length. The following table appeared in Physical Therapy magazine. YOU ARE GOING TO WANT TO WRITE DOWN THIS CHART ON A SEPERATE SHEET OF PAPER IN ORDER TO DO THE CALCULATIONS AND FILL OUT THE CHART. SELF-REPORTED CRUTCH LENGTH HEIGHT IN INCHES IN INCHES PATIENT (X) (Y) 1 64 48.5 2 65 49.0 3 66 49.5 4 67 50.5 5 68 51.0 6 69 51.5 7 70 52.5 8 71 53.0 9 72 54.0 10 73 54.5 11 74 55.0 12 75 56.0 13 76 56.5 COMPUTE THE CORRELATION COEFFICIENT OF THE DATA SET.
Explanation / Answer
Sol)
The correlation coefficient is
r=cov(x,y)/ sd(x)*sd(y)
From Excel
Hence r=0.9985
X Y X 1 Y 0.998495 1