Thread: Adding Different mean numbers

How do I add 3 mean numbers with different standard deviations?

Mean: 642 SD: 24
475 SD: 12
265 SD: 26


I have like 5 different problems that are similar, so instead of an answer, if you can show me how to do it, that would be wonderful. Thanks in advance.

Originally Posted by ASDF1

How do I add 3 mean numbers with different standard deviations?

Mean: 642 SD: 24
475 SD: 12
265 SD: 26


I have like 5 different problems that are similar, so instead of an answer, if you can show me how to do it, that would be wonderful. Thanks in advance.

Please state the question exactly as it's written in your book (or wherever it's come from).

Assuming their scores are independent, what is the team's score and standard deviation?

Originally Posted by ASDF1

Assuming their scores are independent, what is the team's score and standard deviation?

Is that the whole question? I don't see how to do it without more information.

Originally Posted by ASDF1

How do I add 3 mean numbers with different standard deviations?

Mean: 642 SD: 24
475 SD: 12
265 SD: 26


I have like 5 different problems that are similar, so instead of an answer, if you can show me how to do it, that would be wonderful. Thanks in advance.

With out knowing what you are attempting
642 + 475 + 265 = 1382

However, to manipulate the mean it seems as if you must also know the 'n' or number of values to calculate the mean and standard deviation.