Below are the data from a local hospital Using the data abov

Below are the data from a local hospital: Using the data above compute the correlation Lambda (X) using the variables age and blood pressure (choosing the logical variable as the independent). What is the relationship between Age and Blood pressure?

Solution

As correlation can be found out only for numerical variables we assign suitable numerical values for blood pressures.

Normal BP is 80-120

Hence let us give high a value of 140 and low a value of 70.

Similarly young age is between 20-50 hence y = average of 20 and 50 = 35

old age = between 50 and 80 hence average = 65

Rewrite the given data with numerical values

Correlation is positive strong

=0.0704

Note: Here young age and middle age taken from 20 to 50 and 50 to 80.

Second high taken as average 140 and low as 70

	BP	Age
	X	Y
	140	65	9100	19600	4225
	70	35	2450	4900	1225
	70	65	4550	4900	4225
	140	35	4900	19600	1225
	140	35	4900	19600	1225
	70	65	4550	4900	4225
	140	35	4900	19600	1225
	140	65	9100	19600	4225
	70	35	2450	4900	1225
	70	35	2450	4900	1225
	140	65	9100	19600	4225
	140	65	9100	19600	4225
	70	65	4550	4900	4225
	140	35	4900	19600	1225
	70	35	2450	4900	1225
	140	65	9100	19600	4225
	140	35	4900	19600	1225
total	1890	835	93450	230300	44825
		r =	cov (x,y)/sxsy	0.0704