Confidence Tests

Question 1

One sample t - Confidence Interval for a Population Mean

Answer 1

Both POPULATION MEAN and STANDARD DEVIATION unknown:

SRS, normal distribution, no outliers

Question 2

One sample z - Confidence Interval for a Population Mean

Answer 2

POPULATION MEAN unknown:

SRS, normal distribution

Question 3

Two sample t - Confidence Intervals difference of Two Means (compare responses to two treatments)

Answer 3

All POPULATION 1 MEAN / POPULATION 2 MEAN / SD 1 / SD 2 are unknown:

2 SRSs, normal distribution, independent samples

Question 4

One sample - Proportion Confidence for a Population Proportion

Answer 4

Proportion p unknown:

SRS, population at least 10x sample, n = large (np > 10,
n(1-p) >10)

Question 5

Two sample - Proportion Confidence Interval for difference of 2 proportions (compare 2 pop. based on 2 INDEPENDENT samples)

Answer 5

Proportion p1 and p2 unknown:

2 SRSs from 2 distinct pop, pop at least 10x sample, n = large (np1/np2 >5 etc.)