Question

for a data set of the pulse rates for a sample of adult females, the lowest pulse rate is 33 beats per minute, the mean of the listed pulse rates is $\bar{x}=72.0$ beats per minute, and their standard deviation is $s = 13.1$ beats per minute.
a. what is the difference between the pulse rate of 33 beats per minute and the mean pulse rate of the females?
b. how many standard deviations is that the difference found in part (a)?
c. convert the pulse rate of 33 beats per minutes to a z - score.
d. if we consider pulse rates that convert to z scores between - 2 and 2 to be neither significantly low nor significantly high, is the pulse rate of 33 beats per minute significant?
a. the difference is $square$ beats per minute.
(type an integer or a decimal. do not round.)

Explanation:

Step1: Calculate the difference in part a

Subtract the lowest pulse - rate from the mean.
$72 - 33=39$

Step2: Calculate the number of standard - deviations in part b

Divide the difference by the standard deviation.
$\frac{39}{13}=3$

Step3: Calculate the z - score in part c

The formula for the z - score is $z=\frac{x-\mu}{\sigma}$. Here, $x = 33$, $\mu = 72$, and $\sigma = 13$.
$z=\frac{33 - 72}{13}=\frac{-39}{13}=- 3$

Step4: Determine significance in part d

Compare the z - score with the range.
The z - score of the pulse rate of 33 beats per minute is $z=-3$. Since $-3\lt - 2$, the pulse rate is significantly low.

Answer:

a. 39
b. 3
c. - 3
d. Yes