Question

Mean and Standard deviation question!

Answer 1

you know the formulas, right?

Answer 2

No not for this

Answer 3

um what is the formula called?

Answer 4

mean is just the average,
sum all the values and divide by the number of values.

first find mean, you'll need it for std deviation

Answer 5

std deviation is the square root of variance
and
variance is
\(\Large {Var}(X) = \frac{1}{n} \sum \limits_{i=1}^n (x_i - \mu)^2. \)

Answer 6

problem, Im not sure where to put some of the values

Answer 7

\(\Large \mu = \dfrac{1.13+1.02+1.23+1.06+1.16}{5}\)

Answer 8

it is linear so 1.12u

Answer 9

yes, thats mean
now calculate variance using the formula

Answer 10

n = 5

\(\mu\) =1.12

Answer 11

i got 1.25u

Answer 12

\(mean = \mu = 1.12\)

\(\Large {Var}(X) = \dfrac{1}{n} \sum \limits_{i=1}^n (x_i - \mu)^2 \\ \Large = \dfrac{1}{5} [(1.13 - 1.12)^2+(1.02 - 1.12)^2 \\ \Large +(1.23 - 1.12)^2+(1.06 - 1.12)^2 +(1.16 - 1.12)^2] \)

Answer 13

calculating that has nothing to do with statistics

you can use calculator or web to do that calculation for you

Answer 14

ok i got 8.43

Answer 15

http://www.wolframalpha.com/input/?i=+%5Cdfrac%7B1%7D%7B4%7D+%5B%281.13+-+1.12%29%5E2%2B%281.02+-+1.12%29%5E2++%2B%281.23+-+1.12%29%5E2%2B%281.06+-+1.12%29%5E2+%2B%281.16+-+1.12%29%5E2%5D

Answer 16

ok this time i got 0.00685

Answer 17

see the example here,
https://www.easycalculation.com/statistics/standard-deviation.php

Answer 18

Question: is standard deviation and variance considered the same thing? or do I find it now?

Answer 19

they are conceptually different,
but one formula to find variance,
and square root of variance is std deviation

Answer 20

Now, my last question is basically asking if mean and median are or are not conflicting between which is the central value.. right?

Answer 21

When the values of items in the data set are not important BUT the measure which divides the distribution into two equal parts is required, Median is considered as the measure of central tendency
otherwise Mean is considered