Hypothesis Testing

Symbols

200

An alternative hypothesis is detonated as_____

H1

300

In a null hypothesis, the statement is always mu ________ to some number.

=

400

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

population

500

Let z=1.08. We are doing a right tailed test with alpha=0.05. Determine if we reject or fail to reject using the critical region method. Sketch a picture.

z=1.08 and znot = 1.645 

So z falls outside the region ----> We fail to reject Ho

Vocab

100

The null hypothesis is detonated with

Ho

200

If P(value) > alpha then we.......

Fail to Reject Ho

300

When we complete this problems, do we actually prove anything? Explain your answer.

No, .....

400

State the null and the alternate hypothesis's for the following info: The body weight of a healthy 3-month old colt should be about 60. My dad claims it should be lower than that.

Ho: mu=60  and H1: mu <60

500

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

Accept

Sigma is known

100

H1: mu > 30 represents which tailed test?

Right

200

What P(Value) matches with a right tailed test and the z value of 0.90?

0.1841

300

What P(value) matches up with a two tailed test and z=1.98?

0.0239 ----> times 2 -----> 0.0478

400

Find the test statistic z for the following info. Let mu=115, sigma=12, n=6 and x bar=105.

-2.04

500

Determine if we will fail to reject or will reject Ho. 

Let x bar =17.1, sigma=4.5, mu = 19, n=500 and the level of significance =0.05. We want to test if mu is less than 19.

0.0571 ---> Fail to reject Ho.

Sigma is unknown

100

True or False.... When sigma is unknown, we are given a sample standard deviation (s) instead.

True

200

If we don't know sigma, we must find (blank) values instead of z values.

t

300

Find your test statistic t when mu-12.5, s=10, n=21, and x bar=17.1.

2.108

400

To find the correct row to use in the chart, you need to calculate (blank) which is found by taking n-1

Degrees of freedom

500

Find an estimate/interval for the P(value) given the following t value: 2.940?

0.0005 < P(Value) < 0.005

Proportion

100

What is the formula for calculating phat?

r/n

200

What is the formula for calculating the test statistic (z score) of a proportion problem?

z = phat - p/ sprt(pq/n)

300

State the null and alternate hypothsis's.

Let p=0.75. We think the actual proportion is simply different from p.

Ho: p=0.75

H1: p /= 0.75

400

Let alpha = 0.01 and p=0.12. Then, let phat = 0.0766. The sample size is 209. We want to test is if the population is less than 0.12. Find the z score, P(value), and then state whether we reject or not.

0.0268 ---> Fail to reject Ho