Question

The New York City school board wants to estimate the mean size μ of AP statistics classes in New York City high schools. The board obtained the following random sample of AP statistics class sizes:

24 29 29 23 25 24 33 26 24 29 27 26 22 32 24 21 19 29 31 26 29 31 16

Question 1. Use the data above to construct a 95% confidence interval for the mean class size μ. (calculate y and s to 3 decimal places).

lower bound of confidence interval
upper bound of confidence interval

Question 2. Mark the following statement as true or false: The probability is 0.95 that the mean size μ of high school classes is contained in the interval calculated above. One submission ONLY; no exceptions.

True

False    

Answer 1

1)

sample mean         x=	26.043
sample size             n=	23
sample std deviation s=	4.248
std error sx=s/√n=	0.8857

for 95% CI; and 22 df, critical t=		2.0740
margin of error E=t*std error                            =		1.8370
lower bound=sample mean-E =		24.206
Upper bound=sample mean+E=		27.880

2)

False