Question

unit 4 - mean, median and mode, and
the following pulse rates were recorded for a group of 15 students. how many pulse rates were lower than the mean?
84, 74, 87, 68, 82, 68, 71, 75, 65, 62, 75, 74, 66, 82, 62
there were pulse rates lower than the mean.
(type a whole number.)

Explanation:

Step1: Calculate the mean

The mean $\bar{x}=\frac{\sum_{i = 1}^{n}x_{i}}{n}$, where $n = 15$ and $x_{i}$ are the pulse - rates.
$\sum_{i=1}^{15}x_{i}=84 + 74+87+68+82+68+71+75+65+62+75+74+66+82+62=1089$.
$\bar{x}=\frac{1089}{15}=72.6$.

Step2: Count the number of pulse - rates lower than the mean

The pulse - rates lower than 72.6 are 68, 68, 71, 65, 62, 62, 74, 66, 62. There are 9 such values.

Answer:

9