Using the P-Value

1
Using the P-Value

• Section 10.3

2
P-Value (Observed Significance Level)

• Its the measure of the inconsistency between the
  hypothesized value for a population parameter and
  the observed sample statistic.
• How likely is this sample if the Ho is really
  true?

3
Using the P-Value

• Reject if
• Fail to Reject if

4
One tailed test (use the test statistic Z)
P-value
If the Ho is really true, this is the probability
of getting this z-score for the given data
5
Two-Tailed Test
P-Value Sum of both tails
We have to double this to get both tails!
6
Lets try one!
7
Lets try one!
8
For which of the following P-Values would the
null hypothesis be rejected if were using a 0.05
significance level?

• 0.003
• 0.045
• 0.084
• 0.128
• 3.12 x 10-5

9
State whether the observed p-value leads to
rejection of the null at the given significance
level.
10
Find the p-Value associated with each of the
given test statistics (z-scores)
11
Find the p-Value associated with each of the
given test statistics (z-scores)
12
Homework

• Page 546 (2-10) even (11-17, 20, 22, 31)