“In 2016, the mean score on the AP Biology exam was 3.10, with a standard deviation of 1.05. The mean score on the AP US History exam was a 2.74, with a standard deviation of 1.42. What is the combined mean and standard deviation for these exams?”

- Thread starter Janeelise
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“In 2016, the mean score on the AP Biology exam was 3.10, with a standard deviation of 1.05. The mean score on the AP US History exam was a 2.74, with a standard deviation of 1.42. What is the combined mean and standard deviation for these exams?”

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You should have been shown, or somehow discovered along the way...

“In 2016, the mean score on the AP Biology exam was 3.10, with a standard deviation of 1.05. The mean score on the AP US History exam was a 2.74, with a standard deviation of 1.42. What is the combined mean and standard deviation for these exams?”

1) Means are additive. <== Seriously, just add them.

2) Variance is additive. <== What does this suggest concerning the combining of the Standard Deviations?

Everything you said is true, and helpful hints for answering this question. I'm just wondering though: the question isn't asking for aYou should have been shown, or somehow discovered along the way...

1) Means are additive. <== Seriously, just add them.

2) Variance is additive. <== What does this suggest concerning the combining of the Standard Deviations?

You should have been shown, or somehow discovered along the way...

1) Means are additive. <== Seriously, just add them.

2) Variance is additive. <== What does this suggest concerning the combining of the Standard Deviations?

I tried just adding them, and it said I got it wrong.

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What numbers did you add? What result did you obtain? What is the "it" that said your value was incorrect? What value did it provide?I tried just adding them, and it said I got it wrong.

Thank you!