Hypothesis Testing

Hypothesis Testing

100

In a null hypothesis, the sign of the statement is always________.

=

200

The probability of obtaining a sample statistic as extreme as the one obtained if the null hypothesis is assumed to be true is the ______.

P-Value

300

Rejecting a true null hypothesis is called _________ error.

Type I

400

The probability of mistakenly failing to reject a false null hypothesis is _________ error.

Type II

500

The power of a hypothesis test is the probability that a _________ error is not committed.

Type II

Hypothesis Testing

100

When the P-Value is small enough, we say that________ to reject the null hypothesis.

we have evidence

200

The null hypothesis is detonated with

Ho

300

An alternative hypothesis is detonated as_____

Ha

400

In a hypothesis test, we attempt to show that a null hypothesis is unacceptable by showing it is _______.

Improbable

500

Hypothesis tests are designed to measure the _________ of evidence against the null hypothesis.

Strength/ significance of 

Hypothesis Testing

100

The alternative hypothesis is ___________ if there is interest in deviations from the null hypothesis in only one direction.

One-sided

200

The assumptions that must be checked before performing a hypothesis test are:

1.) np and n(1-p) are at least 10 2.) the sample size is less than 10% of the population.

300

A larger sample size results in a ______ power.

larger

400

What is the probability of mistakenly failing to reject a null hypothesis when a hypothesis test is being conducted at the 5% significance level (a=0.05)?

There is insufficient information to answer this question

500

You plan to preform a hypothesis test with the level of significance at .05. What is the effect on the probability of committing a type one error if the sample size is increased?

The probability is unchanged

Hypothesis Testing

100

A hypotheses tests the mean of a sample.  It comes from a normal distribution with n=8 and a normal distribution, the population standard deviation is unknown.  What test should you use?

T -test

200

Always give ________ in your conclusion

Context of your claim

300

State the central limit theorem and explain how it helps us choose which test (z or t) to use.

If n>=30 we can assume normality.  If the sample size is 30 or more we can also say the mean of the sample = population mean and the standard deviation is s/sqrt(n)

400

Choosing a smaller level of significance, that is a smaller a-risk, results in a ______ risk of type II error

A higher risk of type II error

500

A school superintendent must make a decision whether or not to cancel school because of a threatening snow storm. What would the results be of Type I and Type II errors for the null hypothesis: The weather remains dry

Type I: Weather remains dry, school is needlessly canceled Type II: School isn't canceled and the storm hits

Hypothesis Testing

100

Hypotheses are always about the _________, never about the sample.

population

200

We never _______ a null hypothesis; we either do or do not have evidence to reject it.

Accept

300

Is there a time when you cannot use a z or t test?  What is it?

When we cannot show or do not know we have a normal distribution.  

400

If p = .05 and alpha is .03, what is the decision for this test. 

Explain in context.  

Ho:  mean butterfly lifespan<= 7 days (claim)

Ha: Mean butterfly lifespan > 7 days

We fail to reject(do not have enough evidence to reject) the null hypotheses that the mean butterfly life span is <=7 days.

500

What is the probability of committing a type 1 error.  How do you decide.

Significance level

We look at each type of error, decide which is worse and set an appropriate alpha