Chapter 9 Flashcards
Null Hypothesis
Tends to represent the some status quo. I.E Half of freshmen
Alternative Hypothesis
Which represents some possible alternative to that which is established in the null. I.E More than half of freshmen.
P-value
The probability of getting results at least as unexpected as what we observe if the null hypothesis were true.
When the p-value is _____, our observation would be really unlikely if the _____ hypothesis were true
small, null.
When the p-value is _____, our observations happen fairly often just by chance when the ____ hypothesis is correct.
large, null.
Significance level icythys
ictyys-=.05. The cutoff between large and small p-value.
Steps to Performing a Significance Test
1) Identify Hypothesis.
2. Check Conditions for Model- Can we use the normal or T for our sampling distribution?
3. Mechanics- Find the test statistic and p-value.
4) Make conclusions about the hypothesis.
Null Hypothesis
H0:p=p). A placeholder value that is replaced with a value between - and 1
Alternate Hypothesis 3 Forms
Ha:pp0 right tailed test, two tailed teste
Ha: p is not equal to p0 two-way test- two tailed test.
What are the conditions for the model?
Randomization
Sample size np>15. Nq>15. Note make sure to use the null hypothesis value for p and not p hat.
Test Statistic
(p-hat-pzero)/ sqrt[(po)(qo)/n)]
Conclussion
If p-value is less than icythys reject null hypothesisd. There is sufficient evidence at icythys that Ha is true.
If p-value is greater than icythys fail to reject null hypothesis. There is insufficient evidence at icythys that Ha is true.
Null Hypothesis for Means
H0: mu-mu0
Alternate Hypothesis Means
Ha: mumu0 right tailed test, one tailed test.
Ha: mu does not equal mu0 two sided test, two-tailed test.
What’s a good general rule for T vs Z- tests?
T Test for means z test for proportions.
