Question

the list gives the speeds, in miles per hour, of 7 serves made by a professional tennis player. 132, 134, 134, 136, 148, 151, 152 what is the mean speed, in miles per hour, of these 7 serves?

Explanation:

Step1: Calculate the sum of the speeds

$$132 + 134+134 + 136+148+151+152$$
$$=(132+134)+134 + 136+148+151+152$$
$$=266+134 + 136+148+151+152$$
$$=(266 + 134)+136+148+151+152$$
$$=400+136+148+151+152$$
$$=(400+136)+148+151+152$$
$$=536+148+151+152$$
$$=(536+148)+151+152$$
$$=684+151+152$$
$$=(684+151)+152$$
$$=835+152$$
$$=987$$

Step2: Calculate the mean

The formula for the mean $\bar{x}=\frac{\sum_{i = 1}^{n}x_{i}}{n}$, where $n = 7$ (the number of data - points) and $\sum_{i=1}^{n}x_{i}=987$.
So, $\bar{x}=\frac{987}{7}=141$

Answer:

$141$