Question

interpreting data
the resting heart rates for a sample of 15 students are recorded in the following stemplot.
heart rates
5 | 5
6 | 3
6 | 5 9 9 9 9
7 | 0 1 3 3 4
7 | 5 6 7
key: 7|5 = 75 beats per minute
what is the mean resting heart rate for this sample?
70.0 beats per minute
66.0 beats per minute
69.9 beats per minute
69.0 beats per minute

Explanation:

Step1: List all heart rate values

From the stemplot, the values are: 55, 63, 65, 69, 69, 69, 69, 70, 71, 73, 73, 74, 75, 76, 77

Step2: Calculate sum of all values

$55 + 63 + 65 + 69 + 69 + 69 + 69 + 70 + 71 + 73 + 73 + 74 + 75 + 76 + 77 = 1048$

Step3: Compute the mean (sum/number of values)

$\text{Mean} = \frac{1048}{15} \approx 69.9$

Answer:

69.9 beats per minute