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anonymous
 one year ago
Find the population standard deviation (σ not S) for the data set: {75,80,90,95,75,85,55,80,90,95}
Round your answer to the nearest 10th.
anonymous
 one year ago
Find the population standard deviation (σ not S) for the data set: {75,80,90,95,75,85,55,80,90,95} Round your answer to the nearest 10th.

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welshfella
 one year ago
Best ResponseYou've already chosen the best response.1first find the mean of these numbers can you do that?

welshfella
 one year ago
Best ResponseYou've already chosen the best response.1add them all up and divide by 10

welshfella
 one year ago
Best ResponseYou've already chosen the best response.1now you need to find the difference between each number in the list and 82 so for first number 75 it is 82  75 = 7 for 80 it is 82  80 = 2 do this for all the other numbers

welshfella
 one year ago
Best ResponseYou've already chosen the best response.190  82 = 8 and so on

anonymous
 one year ago
Best ResponseYou've already chosen the best response.075=7 80=2 90=8 95=13 75=7 85=3 55=27 80=2 90=8 95=13

welshfella
 one year ago
Best ResponseYou've already chosen the best response.1right strictly it should have been 80  82 = 2 but its not that important because we square each of those results

welshfella
 one year ago
Best ResponseYou've already chosen the best response.1so now we square ach of the 10 results 7^2 = 49 2^2 = 4 and so on

welshfella
 one year ago
Best ResponseYou've already chosen the best response.1when you have done that add them all up then divide the answer by the number of values (10) this result is called the variance find the square root of the variance to get the standard deviation

welshfella
 one year ago
Best ResponseYou've already chosen the best response.1use your calculator  it would be a bit long winded otherwise. It a bit long winded anyway!

welshfella
 one year ago
Best ResponseYou've already chosen the best response.1in the formula x is a number , mu is the mean and N is the total numbers.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.075=7^2=49 80=2^2=4 90=8^2=64 95=13^2=169 75=7^2=49 85=3^2=9 55=27^2=729 80=2^2=4 90=8^2=64 95=13^2=169 1310 divided by 10=131

welshfella
 one year ago
Best ResponseYou've already chosen the best response.1the biig 'E' means 'the sum of'.

welshfella
 one year ago
Best ResponseYou've already chosen the best response.1right i got that too so std dev = sqrt 131

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I'm confused on how to do the equation

welshfella
 one year ago
Best ResponseYou've already chosen the best response.1mu is the mean x  mu is the differences oops sorry i made a mistake with that  the formula is just a summary of the process you have to go through the procedure as we did

welshfella
 one year ago
Best ResponseYou've already chosen the best response.1correct is dw:1438979612906:dw

welshfella
 one year ago
Best ResponseYou've already chosen the best response.1the STd dev comes to 11.45 correct to decimal places

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Is that the answer? Sorry, math is my weakest subject.

welshfella
 one year ago
Best ResponseYou've already chosen the best response.1yes the variance is 131 the standard deviation is the square root of the variance

welshfella
 one year ago
Best ResponseYou've already chosen the best response.1standard deviation gives a measure of the spread of the data

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Oh, ok that makes sense

welshfella
 one year ago
Best ResponseYou've already chosen the best response.1good the lower the standard deviation the closer the data is the mean . If the Std dev is high it means there is a lot of values far away from the mean
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