Question

HELP ME PLS ASAP!!!!!!!!!!!

Answer 1

`\sigma^2=73.96 \ kg^2`

Explanation:

Standard Deviation and Variance

If we have a data set of measured values the variance is defined as the average of the squared differences that each value has from the mean. The formula to calculate the variance is:

`\displaystyle \sigma^2=(\sum(x_i-\mu)^2)/(n)`

Where
`\mu` is the mean of the measured values xi (i running from 1 to n), and n is the total number of values.

`\displaystyle \mu=(\sum x_i)/(n)`

The standard deviation is known by the symbol
`\sigma` and is the square root of the variance. We know the standar deviation of the weight in kg of a group of teenagers to be 8.6 kg. Thus, the variance is

`\sigma^2=8.6^2=73.96 \ kg^2`

`\boxed{\sigma^2=73.96 \ kg^2}`