   SEARCH HOME Math Central Quandaries & Queries  Question from Iris, a student: Help please: me on this type of math problem I can get through step one after that I get lost. Maybe you can explain it to me in a easier way to get the correct results. I have read the examples, but I am still lost cannot move on until the next practice until I get this one Sample standard deviation The following are distances (in miles) traveled to the workplace by employees of a certain computer company. 15,29,32 28 18 28 Find the standard deviation of this sample of distances. Round your answer to at least two decimal places. (If necessary, consult a list of formulas.) The measurements given constitute a sample, and we're asked to compute the sample standard deviation. The sample standard deviation, denoted by , is a measure of the "spread" of the measurements in a sample about their mean . In order to find the standard deviation, we first find the mean of the sample: We then compute the standard deviation as follows: How do I get 232 from these numbers if you could break in down by each step, I know that you Multiply & then add, but what numbers do you Multiply and add together. I am not getting it. I need help (15-25)x2+(29-25)x2+(31-25)x2+(38-25)x2+(18-25)x2+(28-25)x2 over 6-1 I need a step by step hoe the answer is 232 i START LIKE THIS TRYING TO SOLVE (15-25)=-10 10X10=100 YHEN I GET LOST ON THE NEXT THINS TO DO, i DO THIS FOR EACH SET OF NUMBERS. Iris,

You are correct that the mean of the sample is 25 miles.Your process for finding the sample standard deviation is correct but you need to be more careful with the numbers. You need to add

$(15 - 25)^2$
$(29 - 25)^2$
$(32 - 25)^2$
$(28 - 25)^2$
$(18 - 25)^2$ and
$(28 - 25)^2$

and then divide the sum by $6 - 1 = 5.$

Penny     Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.