Chapter 8 Flashcards
what is the critical value also known as?
z*
how do u find the critical value?
use invNorm
put mean as 0, SD as 1
put direction as center!!!!!!
put confidence level as a percentage for the area
how do u find the point estimate?
A + B / 2
how do u find the margin of error?
B - A / 2
how do u find confidence intervals?
statistic (such as p hat) plus/minus the critical value times the standard error
if we’re not given the interval, how do u find the margin of error?
critical value X standard error
as confidence level goes up, the MOE _____
increases
wider interval
as sample size goes up, the MOE _____
decreases
smaller interval
how do u find the standard error?
square root
under the square root: p hat times (1 - p hat) all over n
(for 2 proportions) if the interval is (+,+)
the 1st proportion is greater
(for 2 proportions) if the interval is (-,-)
the 2nd proportion is greater
(for 2 proportions) if the interval is (-,+)
no difference, 0 is contained in the interval
(for calculating margin of error) if not given a p hat, what do we use?
.5
