Question

Assume that blood pressure readings are normally distributed with a mean of 122 and a standard deviation of 8. If 100 people are randomly selected, find the probability that their mean blood pressure will be less than 124. T O A. 0.0062 OB. 0.9938 OC. 0.8819 O D. 0.8615 TART HERE EBBEACH BOLSAS DRESS SES THE DARI ER

Answer 1

Solution :

Given that ,

mean = $\mu$ = 122

standard deviation = $\sigma$ = 8

n = 100

$\mu$$\bar x$ = 122

$\sigma$$\bar x$ =$\sigma$  / $\sqrt$ n = 8/ $\sqrt$ 100=0.8

P($\bar x$ <124 ) = P[($\bar x$ - $\mu$ $\bar x$ ) / $\sigma$ $\bar x$ < (124 -122) / 0.8]

= P(z < 2.5)

Using z table  

probability=0.9938