Question

each of the 6 cats in a pet store was weighed. here are their weights (in pounds).
11, 15, 9, 9,
find the mean and median weights of these cats.
if necessary, round your answers to the nearest tenth.
(a) mean: pounds
(b) median: pounds

Explanation:

Step1: Calculate the mean

The formula for the mean $\bar{x}=\frac{\sum_{i = 1}^{n}x_{i}}{n}$. Here, $n = 6$ and $x=\{9,9,11,15,15\}$.
$\sum_{i=1}^{6}x_{i}=9 + 9+11+15+15=69$
$\bar{x}=\frac{69}{6}=11.5$

Step2: Calculate the median

First, order the data: $9,9,11,15,15$. Since $n = 6$ (even), the median $M=\frac{x_{\frac{n}{2}}+x_{\frac{n}{2}+1}}{2}$.
$x_{\frac{6}{2}}=x_{3}=11$, $x_{\frac{6}{2}+1}=x_{4}=15$
$M=\frac{11 + 15}{2}=\frac{26}{2}=13$

Answer:

(a) Mean: $11.5$ pounds
(b) Median: $13$ pounds