Question

In 2016, the mean score on the AP Statistics exam was 2.80, with a standard deviation of 1.35. The mean score on the AP Calculus exam was a 2.86, with a standard deviation of 1.55. What is the combined mean and standard deviation for these exams?

Answer 1

Answer:

Combined mean=5.66

Combined standard deviation = 2.06

Step-by-step explanation:

Combined mean= (MXa+ n×Xb)/(m+n)

Combined mean =2.80+2.86=5.66

Combined mean= sqrt(1.55)^2+(1.35)^2)

Combined deviation = 2.06

Answer 2

Answer:

c. Mean, 5.66; standard deviation, 2.055

Step-by-step explanation:

you add the means of each test to get the combined mean

then you add the standard deviations when they are each to the second power (ex: 1.35²+1.55²) then you find the square root of the sum of those     (ex: √4.225)