Diastolic blood pressures are assumed to follow a normal distribution with a mean of 85 and a standard deviation of 12. a. What proportion of people have diastolic blood pres- sure less than 90

The probability that  people have diastolic blood pressure less than 90

P( X< 90) = 0.6628

Step-by-step explanation:

Explanation:-

Given mean of the Population 'μ'= 85

Given standard deviation of the Population 'σ'= 12

Let 'X' be the Normal distribution

let X = 90

The probability that  people have diastolic blood pressure less than 90

P( x < 90) = P( Z < 0.4166)

               = 1 - P( Z> 0.4166)

               = 1 -  (0.5 - A( 0.4166)

               = 0.5 + 0.1628

               = 0.6628

Conclusion:-

The probability that  people have diastolic blood pressure less than 90

P( X< 90) = 0.6628

68%

Step-by-step explanation:

IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. About 68% of individuals have IQ scores in the interval 100 ± 1 ( 15 ) = [ 85 , 115 ] .