Transcript Using the P

Using the P-Value
Section 10.3
P-Value (Observed Significance Level)

It’s the measure of the inconsistency between
the hypothesized value for a population
parameter and the observed sample statistic.
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How likely is this sample if the Ho is really
true?
Using the P-Value
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Reject H o if p  value  
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Fail to Reject H o if p  value  
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
Two-Tailed Test
P-Value: Sum of both tails
P( z  1.0607)  ncdf (, 1, 0607)  0.1444
We have to double this to
get both tails!
Let’s try one!
 H o : p  0.5

 H A : p  0.5
z  1.75
  0.05
Let’s try one!
 H o : p  0.5

 H A : p  0.5
z  2.02
  0.01
For which of the following P-Values would the null hypothesis
be rejected if we’re using a 0.05 significance level?
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0.003
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0.045
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0.084
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0.128
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3.12 x 10-5
State whether the observed p-value leads to rejection of the null
at the given significance level.
p  Value  0.079
  0.10
p  Value  0.028
  0.01
p  Value  0.056
  0.05
p  Value  0.21
  0.10
Find the p-Value associated with each
of the given test statistics (z-scores)
 H o : p  .6

 H A : p  .6
z  0.86
z  2.31
Find the p-Value associated with each
of the given test statistics (z-scores)
 H o : p  .6

 H A : p  .6
z  2.21
z  0.97
Homework
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Page 546 (2-10) even (11-17, 20, 22, 31)