Terms

Question 1

Hø

Answer 1

The null hypothesis

Question 2

Ha

Answer 2

The alternate hypothesis

Question 3

What is a z test and how can you determine when to use one?

Answer 3

A z test is used for large samples. When the sample size is greater than 30, a z test can be used.

Question 4

σ

What does the symbol represent?

Answer 4

Standard deviation

Question 5

n

What does the symbol represent?

Answer 5

Sample size

Question 6

Type II Error

Answer 6

Failure to reject when null hypothesis is not true.

Question 7

Type I Error

Answer 7

When a null hypothesis
is wrongly rejected.

Question 8

When should you use a Type II error?

Answer 8

We use a Type II error when the null hypothesis is false.

Question 9

What is a right tailed test ?

Answer 9

When your hypothesis statement contains a greater than symbol. In word problems, words like “increased” help determine if it’s a right tailed test.

Question 10

a

What does the symbol represent?

Answer 10

significance level

Question 11

confidence level

Answer 11

The percent of confidence
intervals that contain the true
population parameter when
repeated samples are taken

Question 12

critical value

Answer 12

A measure of how many standard errors above or below the center of the confidence interval to go to achieve the desired level of
confidence

Question 13

degrees of freedom

Answer 13

A measure related to the sample size (n) derived from the calculation of the sample standard deviation. Formula for a t-distribution: n-1

Question 14

margin of error

Answer 14

A quantity that can be added or subtracted from a point estimate to construct a confidence interval.

Question 15

margin of error

Answer 15

A quantity that can be added or subtracted from a point estimate to construct a confidence interval.
Formula: Critical Value x Standard
Error

Question 16

Two tailed test

Answer 16

Where the critical area of a distribution is two sided and test if a sample is greater or less than a range of values. In a word problem, worlds like “differed” tell us it’ll be a two tailed test.

Question 17

What is a t test and how can you determine when to use one?

Answer 17

A t test is used when standard deviation is unknown and there are two or fewer groups. We can determine when to use one when we are given sample standard deviation and the sample size is less than 30 or small.