Hypothesis Testing
Decisions
Z test
T Test
2 sample tests
100
Write the statement as a null or alternative hypothesis:
A state park claims that the mean height of oak trees is at least 85 feet
100
if p = .04 and a = .01
Do you reject or fail to reject Ho?
Fail to reject
100
Can you support the claim?
YES! The claim is Ho and the p value is .127902 which is greater than the significance level of .10. We do not reject Ho so we also do not reject the claim.
100
When do we use T over Z?
When sample size is less than 30
100
Should Z or T be used?
Z
200
Write the statement as a null or alternative hypothesis
A light bulb manufacturer claims that the mean life of a certain type of light bulb is more than 750 hours
m > 750
200
if p = .04 and a = .01
If Ha is the claim, is the claim supported by the evidence?
Ha is not supported by the evidence
200
Can you support the claim?
NO! The claim is Ha but the p value .061782 is greater than the significance level of .05. Therefore you do not reject Ho. Ha is not supported
200
73What is the p value?
The P value is .98255
200
What is the p value?
Very low!! .0000000616948 or 6.16948 x 10^-8
300
Which claim is being evaluated Ho or Ha?
A scientist claims that the mean incubation period for swan eggs is less than 40 days
Ha
300
if p = .04 and a = .05
Do you reject or fail to reject Ho?
Reject Ho
300
Can you support the claim?
No! Ho is the claim and it is rejected because the p value of .031486 is less than the significance level of .08. Ho is rejected, therefore the claim is also rejected.
300
What is the p value?
The p value is .001322
300
Is there a difference in score for these two teachers? not pooled a= .05
There is no statistical difference between the two. Since P value is .37924 with a significance level of .05 we would not reject Ho. Ho would be m1 = m2
400
Which claim is being evaluated Ho or Ha?
A sports drink maker claims the mean calorie content of its beverages is 72 calories per serving
Ho
400
if p = .04 and a = .1
If Ha is the claim, is the claim supported by the evidence?
Yes
400
No! The p value is .919952 and the significance level is .05. You do not reject Ho. Since the claim is Ha, it cannot be supported.
400
Do you reject the null hypothesis? pooled
Yes! Reject Ho, the p value is .088176 and the significance level is .10. P value too low... Reject Ho!