Question

Find the mean and standard deviation of each data set. Round to the nearst hundredth.

1. 4 8 5 12 3 9 5 2

2. 102 98 103 86 101 110

3. 8.2 11.6 8.7 10.6 9.4 10.1 9.3

Answer 1

do you have to do them by hand? or can you use a calculator? or excel even?

Answer 2

@amistre64 We can use a calculator but we have to show the work. I'd just like to know the problems step-by-step :)

Answer 3

the mean of a set is the sum of the parts, divided by how many parts there are.

Answer 4

So the mean is 6, for the first one.

Answer 5

the standard deviation of a population set .... is the square root of variance

variance is a little tricky to put into words, but is basically the mean of the squares of the "zeroed out" set

Answer 6

sum{4 8 5 12 3 9 5 2} = 48

there are 8 data points ... mean is 48/8 = 6 yes

Answer 7

now, the variance is simple enough to perform, just zero out set: subtract the mean from all the elements

Answer 8

{4 8 5 12 3 9 5 2} - 6

-2 2 -1 6 -3 3 -1 -4 square these results and take the mean of the squares

4 4 1 36 9 9 1 16

sum{4 4 1 36 9 9 1 16} = 80

variance = 80/8, std dev = sqrt(variance)

Answer 9

to "show your work" you prolly have to structure it into a table ... and prettify it

Answer 10

So is the final answer 9?

Answer 11

the final answer ... mean = 6
sd = sqrt(8)

Answer 12

@amistre64 So is the answer "sqrt(8) = 3" or is it just "sqrt(8)"

Answer 13

I got 3 for standard deviation and 6 for mean, can someone confirm this for me?