anonymous
  • anonymous
What is the standard deviation of the following data? If necessary, round your answer to two decimal places. 12, 13, 8, 13, 9, 11, 12, 9, 1
Mathematics
  • Stacey Warren - Expert brainly.com
Hey! We 've verified this expert answer for you, click below to unlock the details :)
SOLVED
At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga. Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus. Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.
katieb
  • katieb
I got my questions answered at brainly.com in under 10 minutes. Go to brainly.com now for free help!
jtvatsim
  • jtvatsim
I don't think @heretohelpalways that we want the mean absolute deviation for this problem. We need the standard deviation.
jtvatsim
  • jtvatsim
The steps to do this are: 1. Find the mean of the data. (Find the average) 2. Then find subtract each data point from the mean and square the result. 3. Find the mean of the "square differences" we found in step 2. 4. Take the square root of Step 3 and we are done. This is easier to see in a table. Which I will show below.
jtvatsim
  • jtvatsim
Here's the start of my table.
1 Attachment

Looking for something else?

Not the answer you are looking for? Search for more explanations.

More answers

jtvatsim
  • jtvatsim
Let's go ahead and do step 1. What is the mean of the data? To do this, just add up all the data and divided my how many we have.
anonymous
  • anonymous
9.8?
jtvatsim
  • jtvatsim
12 + 13 + 8 + 13 + 9 + 11 + 12 + 9 + 1 = 88 Then, divide this by 9 (that's how many we have), this gives us 88/9 = 9.8. You beat me! Good! :D
jtvatsim
  • jtvatsim
Now, for the annoying part... we have to subtract the mean from each of our data points. So, for example, we do 12 - 9.8 = 2.2. Then we repeat this for all the other points... BORING! But, not that hard. :)
jtvatsim
  • jtvatsim
When you are done, you will get something like this (I'm cheating since I have a computer that does this for me...)
1 Attachment
jtvatsim
  • jtvatsim
Does that make sense so far?
anonymous
  • anonymous
Yep! got it so far, thanks
jtvatsim
  • jtvatsim
Great! Now, for the second part of Step 2. We need to "square" (multiply the number by itself) each of the differences we just found. What am I trying to say? For example, The first difference was 2.2. So find 2.2^2 = 2.2 * 2.2 = 4.84. And do this for each of the differences... BORING AGAIN! But not hard.
jtvatsim
  • jtvatsim
You should get something that looks like this
1 Attachment
jtvatsim
  • jtvatsim
Phew! Almost done! Now, we find the mean (average) of these crazy squared numbers. Add them up, divide by how many (9) and we get: 12.6 about.
jtvatsim
  • jtvatsim
This number we just found is called the "variance" of the data. The standard deviation is the square root of this number. So just find sqrt(12.6) = 3.6 and we are done.
anonymous
  • anonymous
Got it! Thank you so much, that was very well explained!
jtvatsim
  • jtvatsim
Glad to help! No point to make it harder than it already is! :) Good luck!

Looking for something else?

Not the answer you are looking for? Search for more explanations.