a study conducted in a hospital throughtout a year indicated

a study conducted in a hospital throughtout a year indicated that maternal mortality rate and drug addiction have a correlation coefficient of 0.45. the number of dead births and number of mothers and the number of mothers saying on maternity department who has drug addiction are recorded each month; and their standard devoation are 2.2 and 10.3 respectively, what is the covariance between maternal mortality rate and drug addiction?

Solution

we know correlation coefficient=covariance/{sd of mortality rate*sd of drug addiction}

or, 0.45=covariance/{2.2*1.03}

or covariance=0.45*{2.2*1.03}=1.0197

so the covariance between maternal mortality rate and drug addiction is 1.0197 [answer]