STATS: 2 samp

Question 1

when every # in the interval is larger than 0 that means…

Answer 1

there was change (no change would be 0)

Question 2

Interval –>

Answer 2

PANIC

Question 3

Test –>

Answer 3

PHANTOMS

Question 4

POI statement (for BOTH):

Answer 4

The POI is the true DIFFERENCE in (means/proportions) between group 1 and group 2.

Question 5

Assumptions for proportions

Answer 5

-random sample (for both groups)
-10% condition (for both groups)
-n1(p1) n1(q1) ~ n2(p2) n2(q2) ~ greater than equal to 10 (for approx. normal)

use p-hat for proportion-tests

Question 6

2-Prop Z Int

Answer 6

define z* and interval

Question 7

Conclusion for 2 sample INTERVALS

Answer 7

We are __% confident that the true DIFFERENCE in (proportions/means) between group 1 and group 2 is between __ and __.

Question 8

Assumptions for means

Answer 8

-random sample (for both groups)
-10% condition (for both groups)
-for approx normal:
~both populations are normal
~n greater than or equal to 30 (CLT)
~graph: no strong skew or potential outliers for both data sets

Question 9

2-Samp T Int

Answer 9

define t* and interval

Question 10

2-Samp T Test

Answer 10

define t-value and p-value

Question 11

2-Prop Z Test

Answer 11

define z-value and p-value

Question 12

ALWAYS STATE YOUR …

Answer 12

SIGNIFICANCE LEVEL (for tests)

Question 13

p-value < significance level

Answer 13

reject H0, stat. sig –> we DO have convincing evidence

Question 14

p-value not< significance level

Answer 14

fail to reject H0, not stat. sig –> we DO NOT have convincing evidence

Question 15

Conclusion for 2-sample tests

Answer 15

We do/do not have convincing evidence of a different (average/proportion) of ____ between group 1 and group 2

Question 16

Hypotheses for proportions

Answer 16

Ho: p1=p2
Ha: p1<,>,not=to p2

Question 17

Hypotheses for means

Answer 17

Ho: M1=M2
Ha: M1<,>,not=to M2

Question 18

Hypotheses are used for …

Answer 18

tests !! (PHANTOMS)

Question 19

write down the memorization phrases:

Answer 19

605-ZAp-hat
42-CLT8x

Question 20

when looking for a matched pair …

Answer 20

-before and after (of ONE group)
-when subjects are paired then assigned different treatments
-if each subject got both treatments and your comparing effects of treatments

Question 21

when looking for 2 sample …

Answer 21

-completely randomized design
-when comparing 2 SEPARATE groups
(look to find 2 DIFFERENT groups in a question)

Question 22

when looking for the amount of time…

Answer 22

MEANS

Question 23

when someone does something PER DAY …

Answer 23

MEANS

Question 24

key words for intervals

Answer 24

-estimate(difference)
-find
-describe

Question 25

key words for tests

Answer 25

-when needing to answer a question
-to find enough evidence
-comparing
-suggest

Question 26

don’t forget to …

Answer 26

assign which group is group 1 and group 2!!

Question 27

A double blind experiment …

Answer 27

reduces bias (hippocratic oath)

Question 28

for matched pairs …

Answer 28

-POI is the true AVERAGE DIFFERENCE between…
-Ho: M=0
Ha: M<,>,not=to 0
-matched pair t-test for M