STATS 302: Exam 2

Sampling distribution

Repeatedly taking samples and plotting their sample averages.

Data Distribution

Taking one sample and looking at individual measurements.

Population distribution

Measuring everyone in the entire population.

Null hyppothesis

Represents the original claim

Alternative hypothesis

Represents what the reaseacher is trying to find evidence for

Reject null

We have suffieicnet evidence supporting alternative hypothesis

Fail to reject null

We DO NOT have sufficient evidence supporting alternative hypothesis

Type one error

False positive

Type 1 error

False positive

• when we reject a null hypothesis that is actually true

• False alarm

Type 2 error

False negative

• when we fail to reject the null hypothesis that is actually false

• Missed detection

alpha

Probability of making type 1 error

beta

probability of making type 2 error

90% Z star

1.65

95% Z star

1.96

99% Z star

2.57

P value

Measures how suprising our sample result would be if the null hypothesis were actually true

Larger sample size

Smaller standard error and narrow Confidence interval

Sampling distribution of the sample mean- will decrease

Smaller Sample size

Larger standard error and wider confidence interval

Widest confidence interval

Smallest sample size and highest confidence interval

P0

the claimed population proportion we are testing

P hat

what we are actually observing in our sample