Question

Diastolic blood pressures are assumed to follow a normal distribution with a mean of 85 and a standard deviation of 12.

* If a sample of 15 participants are sampled, what is the probability that their mean diastolic blood pressure exceeds 90?
* Describe a study you could conduct on this population using one of the qualitative data collection methods you’ve learned about previously.

Answer 1

Solution :

Given that,

mean = = 85

standard deviation = = 12

n = 15

= 85

= / n = 12 / 15 = 3.0984

P( > 90) = 1 - P( < 90 )

= 1 - P[( - ) / < ( 90 - 85) / 3.0984 ]

= 1 - P(z < 1.61)

Using z table,    

= 1 - 0.9463

= 0.0537

Probability = 0.0537