math

posted by .

find the standard deviation for the following: 8,5, 12, 8, 9, 15, 21, 16, 3. There is a formula but our teacher wants us to do it a specific way.

For example, 47, 41, 32, 53, 57. First you find the mean, which is 46 and then subtract it with each number in the set so you get 1, -5, -14, 7, 11. then you square each # to get 1, 25, 196, 49, 121. then add all the numbers to get 392 & you do 392/n-1 (n being how many #s there are in the set) so 392/5-1 = 98 then you square root 98 & the standard deviation is 9.9.

For 8, 5, 12, 8, 9, 15, 21, 16, 3 the standard deviation is 5.73973 but when i tried the process i get a completely different answer. First the i found the mean, which is 10.77777778. (97/9) but after this i started messing up, help? Can't use the formula!

• Math -

if you have a graphing calculator, go to catalog (normally you can get there by hitting the 2nd button than 0), then hit the alpha button and hit T then scroll up to stdDev which is standard deviation, hit enter, then type in the bracket (to get to is 2nd button then parantheses), type in the numbers you need with a comma in between each number, end the bracket AND end the parantheses then hit enter and there's your answer. always trust a calculator more than written out because of the issue of human error

Similar Questions

1. Physical Fitness

We have an assignment and this is all about the physical fitness. First, we will have our warm-up then we will have our exercises. Our teacher said that our exercises are arm span, curl-ups and etc. but we don't know how to do it... …
2. Math

Roughly speaking, the standard deviation indicates how far, on average, the observations are from the mean. Do you think that for the data set below the standard deviation will give a good indication of the typical deviation from the …
3. math

hi i need help calculating the standard error using the central limit theorem. *a population of scores contains exactly 5 scores : 2, 3, 6, 8, 11, there are 5x5=25 samples of the two scores (n=2)* i already calculated the standard …
4. Statistics

hi i need help calculating the standard error using the central limit theorem. *a population of scores contains exactly 5 scores : 2, 3, 6, 8, 11, there are 5x5=25 samples of the two scores (n=2)* i already calculated the standard …
5. Math: Statistics

My homework has a list of numbers and I'm working with standard deviation. I know the standard deviation as well as the mean and everything, but it says to find "the weight that is 3 standard deviations below the mean." What is the …
6. MATH

A mean score on a standardized test is 50 with a standard deviation of 10. Answer the following a. What scores fall between –1 and +1 standard deviation?
7. statistics

What type of statistical information would I include in my report to determine our year-to-date performance of our division; example, mean, median, or standard deviation.
8. Statistics

Given that x is a normally distributed random variable with a mean of 28 and a standard deviation of 7, find the following probability: P(x<28) I understand that the means is 28 and the standard deviation is 7. However what I don't …
9. stats

Why must you square the deviation scores when computing a standard deviation using the definitional formula?
10. math

find the standard deviation for the following: 8,5, 12, 8, 9, 15, 21, 16, 3. There is a formula but our teacher wants us to do it a specific way. For example, 47, 41, 32, 53, 57. First you find the mean, which is 46 and then subtract …

More Similar Questions