Cases for which test

Question 1

Confidence Interval for Estimating a Population Proportion p

Answer 1

p^ +/- E

Where E = z_a/2 * sqrt( p^q^ / n)

Question 2

Sample Size Required to Estimate a Population Proportion

Answer 2

With known sd (rare):
n = (z_a/2 ^2 * p^q^)/E^2

where E = desired margin of error

Question 3

Confidence Interval for Estimating a Population Mean with S Not Known

Answer 3

x^bar +/- E

Where
x^bar = sample mean
E = margin of error defined as t_a/2*(s/sqrt(n))
s = sample variance

Question 4

Sample Size Required to Estimate a Population Mean

Answer 4

n = ( (z_a/2 * sd) / E )^2

Where E = desired margin of error (given)

Question 5

Confidence Interval for Estimating a Population Mean with S Known

Answer 5

x^bar +/- E

Where
x^bar = sample mean
E = margin of error defined as z_a/2*(sd/sqrt(n))
s = sample variance

Question 6

Testing a Claim About a Population Proportion

Answer 6

x = successes
p^ = x/n
q^ = 1-p^
z = (p^ - p)/sqrt((p*q)/n)

important: p*q are not the hats

Question 7

Testing Claims About a Population Mean (with S Not Known and known)

Answer 7

Not known:
t = (x^bar - mu_x) / (s/sqrt(n))

known:
replace s with sd

Question 8

Test a claim about two population proportions or

Answer 8

p^bar = x1 + x2) / (n1 + n2

z = p^bar_1 - p^bar_2 ) - ( p_1 - p_2)
_________________________
sqrt( (p^barq^bar)/n_1 + (p^barq^bar)/n_2 )

Question 9

Test through construct a confidence interval estimate of the difference
between two population proportions.

Answer 9

p^hat_1 - p^hat2 +/- E

where E =z_alpha/2 * sqrt( (p^barq^bar)/n_1 + (p^barq^bar)/n_2 )

if 0 is not in the CI, the proportions are not equal

Question 10

Test of a claim about two independent population means

Question 11

Test through confidence interval estimate of the difference between two independent population means.