Exam 3 Review

Question 1

Normal Distribution Criteria

Answer 1

Proportions: np > 10 and n(1-p) > 10
Means: n must be > 30, with dot plot that don’t have extreme skewness or outliers

Question 2

Z-score

Answer 2

The number of standard deviations an observed statistic is from the mean

Question 3

Z stat

Answer 3

Used for proportions, tells where the sample falls on the distribution in SE units

Question 4

T stat

Answer 4

Where the sample is on a sampling distribution for means

Question 5

T*

Answer 5

Used to calculate CI for means by hand

Question 6

Z*

Answer 6

Used to calculate the CI for proportions by hand

Question 7

R^2

Answer 7

Percentage of variability in Y that can be explained by the model

Question 8

Residuals

Answer 8

Difference between predicted and actual values

Question 9

Normal distribution

Answer 9

Follows a bell shaped curve, the shape of which is determined by the mean and standard deviation

Question 10

Standard normal distribution

Answer 10

Has a mean of 0 and a st dev of 1

Question 11

Test statistic formula

Answer 11

(Sample stat - null parameter)/ SE