Question

Find the variance and standard deviation. Round your answers to the nearest tenth; write your answers separated by commas; example: 14.0; 5.8
{10, 12, 14, 15, 18, 20, 23}

Answer 1

\[\sigma=\sqrt{\frac{\sum_{i=1}^{n}{x_{i}^2}}{n}-\mu^2}\]Just square whatever you get for that to find the variance.

Answer 2

didnt understand one thing.

Answer 3

You're not familiar with that notation?! Basically, what it says is: square each value, then add them all up, then divide by the number of values, then subtract the mean.

Answer 4

mean squared*

Answer 5

sum all the: (x-u)^2 and divide by the number in the population to get variance right?

Answer 6

Yeah but the formula I put up there is quicker.

Answer 7

thats why they call it a shortcut :)

Answer 8

Yup :)

Answer 9

my ti83 say: ox = 4.24...

Answer 10

so o^2 = 17.64 or so?

Answer 11

I got variance as 18.