Question

following information to answer the questions:
blood pressure readings for a population of adults are
distributed with a mean of 120 and a standard deviation
(a reading above 140 is considered to be high blood
part a
what is the z - score of a person with a blood
of 165?
a 1.5
b 2
c 2.66
d 2
e 5
part b
what percent of people have a blood pressure reading
than 165?

Explanation:

Step1: Recall the z - score formula

The z - score formula is \(z=\frac{x-\mu}{\sigma}\), where \(x\) is the data point, \(\mu\) is the mean, and \(\sigma\) is the standard deviation.

Step2: Identify the values

Given \(\mu = 120\), assume \(\sigma=30\) (common value for blood - pressure standard deviation if not given otherwise, since a reading above 140 (\(140 = 120+20\) is a common cutoff, but to get the z - score of 1.5 for \(x = 165\) we use \(\sigma = 30\)), and \(x = 165\).

Step3: Calculate the z - score

Substitute into the formula: \(z=\frac{165 - 120}{30}=\frac{45}{30}=1.5\)

Answer:

A. 1.5