Stat 121 Choosing the right method

Question 1

Testing a claim or checking to see if groups are different?

Answer 1

Hypothesis test

Question 2

Estimating the value of a parameter?

Answer 2

Confidence interval

Question 3

One group with quantitative response (working with means)?

Answer 3

1-sample t-test for means
—OR—
1-sample t-interval for means

Question 4

One group with categorical response (working with proportions)?

Answer 4

1-sample z-test for proportions
1-sample z-interval for proportions

Question 5

PAIRED DATA / Matched pairs with quantitative response (working with means)?

Answer 5

Matched pairs t-test for means
Matched pairs t-interval for means

(Note: use the 1 sample t
formulas but with 𝑑̅ in place of
𝑥̅ and sd in place of s)

Question 6

2 GROUPS quantitative response (working with means)?

Answer 6

2-sample t-test for means
2-sample t-interval for means

Question 7

2 GROUPS categorical response (working with proportions)?

Answer 7

2-sample z-test for proportions
2-sample z-interval for proportions

Question 8

2 GROUPS categorical response with more than 2 options (working with proportions)?

Answer 8

Chi-squared Test for independence

Question 9

3+ groups quantitative response (working with means)?

Answer 9

Anova (f-test)

Question 10

3+ groups categorical response (working with proportions)?

Answer 10

Chi-squared Test for independence

Question 11

Using Quantitative X to predict Y quantitative response (working with means)?

Answer 11

T-test for slope of regression line