Round your answer to one decimal placeSolutionlet X be the r

Round your answer to one decimal place.

Solution

let X be the random variable denoting the life (in months) of aouto batteries of this brand.

assuming X~N(44,3²)

so P[35<X<53]=P[(35-44)/3<(X-44)/3<(53-44)/3]=P[-3<Z<3]   where Z~N(0,1)

                      =P[Z<3]-P[Z<-3]=0.9973 [using empirical rule]

so the percentage of auto batteries of this brand that have a life of 35 to 53 months is 99.73% [answer]