Question

systolic blood pressure readings for a population of adults are normally distributed with a mean of 125 and a standard deviation of 10. (a reading above 140 is considered to be high blood pressure.) begin by converting the given blood pressure reading into a z - score. then use the accompanying table of z - scores and percentiles to find the percentage of people with blood pressure readings below 140.
click the icon to view the table of z - scores and percentiles
the z - score is 1.5
(type an integer or a decimal.)
the percentage of people with blood pressure readings below 140 is %
(round to two decimal places as needed)

Explanation:

Step1: Find the z - score

The formula for the z - score is \(z=\frac{x-\mu}{\sigma}\), where \(x = 140\), \(\mu=125\), and \(\sigma = 10\).
\(z=\frac{140 - 125}{10}=\frac{15}{10}=1.5\)

Step2: Find the percentage using the z - score table

Looking up the z - score of \(z = 1.5\) in the standard normal distribution table (z - score and percentile table). The value corresponding to \(z = 1.5\) is \(0.9332\)

Answer:

\(93.32\%\)