4) Given the set of scores 5.4, 5.6, 5.7, 5.9, 6.0; find the standard deviation.

Question

anonymous · Answer

average = $$\frac{ 5.4 + 5.6 + 5.7 + 5.9 + 6 }{ 5 } = 5.72$$

variation = $$\frac{ (5.4 - 5.72)^2 + (5.6 - 5.72)^2 + (5.7 - 5.72)^2 + (5.9 - 5.72)^2 + (6 - 5.72)^2}{ 5 } = 0.0456$$

standard deviation = $$\sqrt{variation} = \sqrt{0.0456} = 0.213542$$

anonymous · Answer

ok so what is the viriation

anonymous · Answer

ok I have another question 2) A local car dealership advertises cars that get the following miles per gallon:15, 22, 36, 30, 38, 21 Find the variance. (Round your answer to the nearest hundreth.)  do you do it the same way

anonymous · Answer

Yes, variation is just how the numbers vary from the average. You just calculate the average of 15,22,36,30,38,21 and then $$\frac{(15-avg)^2+(22-avg)^2 ....}{5}$$Got it ? :)

anonymous · Answer

It should be divided by 6, sorry

anonymous · Answer

ok

anonymous · Answer

I have another question

anonymous · Answer

5) Eight golfers posted the following scores during the tournament: 78, 75, 82, 85, 74, 80, 80, 82
Find the standard deviation. (Round your answer to the nearest hundreth.)

anonymous · Answer

so far I know the average is 480.71

anonymous · Answer

and I did 78-480.71+75-480.71........ and I got -4440.81

anonymous · Answer

you have to square the numbers you substract so it should be $$(78-480.71)^2+(75-480.71)^2$$ and so on

anonymous · Answer

and i got the answer - 4440.81

anonymous · Answer

what do i do now

anonymous · Answer

so you do the variation and the standard deviation  the same way

anonymous · Answer

k first of all the average is not 480.71 but 79.5 (You sum up all the scores and divide by the number of scores you have.

After that you calculate the variation as follows 

$$\frac{(78-79.5)^2+(75-79.5)^2+(82-79.5)^2+(85-79.5)^2+(74-79.5)^2+(80-79.5)^2+(80-79.5)^2+(82-79.5)^2}{8}$$

after that you take the square root of variation which is the standard deviation

$$\sqrt{12}=3.46$$

done

anonymous · Answer

so you do the variation and the standard deviation  the same way

anonymous · Answer

i did 74+75+78+80+80+82+82/7 and that's how i got the average

anonymous · Answer

i got 23.9622098313156 as the answer