Question

Part 1 (15 points)Find the mean (4 points), median (3 points) and standard deviation (8 points) for thissample of students' weights.129 lbs, 181 lbs, 158 lbs, 143 lbs, 172 lbs, 118 lbs, 130 lbs and 213 lbs

Answer 1

Given:

129 lbs, 181 lbs, 158 lbs, 143 lbs, 172 lbs, 118 lbs, 130 lbs and 213 lbs

Mean:

$\text{Mean}=\frac{\Sigma x}{n}$$\text{Mean}=\frac{129+181+158+143+172+118+130+213}{8}$$\text{Mean}=\frac{1244}{8}$$\text{Mean}=155.5$

Median:

Ascending order : 118,129,130,143,158,172,181,213

There are 8 terms that is n is even

$\text{Median}=\lbrack(\frac{n}{2})^{th\text{ term}}+(\frac{n}{2}+1)^{th\text{ term}}\rbrack\frac{.}{.}2$$\text{Median=\lbrack{}4th term + 5th term\rbrack/2}$$\text{Median}=\frac{\lbrack143+158\rbrack}{2}$$\text{Median}=150.5$

Standard Deviation:

$\sigma=\sqrt[]{\frac{\Sigma|x-\mu|}{N}}$$\sigma=\sqrt[]{\frac{32.5+21.5+20.5+7.5+7.5+21.5+30.5+62.5}{8}}$$\sigma=\sqrt[]{\frac{204}{8}}$$\sigma=5.0498$