Your Turn:
c. calculate a 95% confidence interval estimate of the difference between average spending in 2013 to
2014.
10.2 Comparing Two Population Means with σ
1
and σ
2
un
known
We are going to use an excel add-in as a shortcut for these hypothesis tests.
The name of the add-in is called
Excel’s _Data analysis_ Tools.
We must have _enabled_ data in order to use this tool.
This tool is _is_
available for Mac users.
Please see the installation instructions document posted in Canvas with the Chapter
10 files to assist you in getting this tool added to your PC.
Together we will work this problem:

Your Turn:

10.4: Comparing Two Population Proportions p.470
Hypothesis tests on the difference between two proportions: p.473
Step 1: Identify the null and alternative hypotheses.
Step 2: Set a value for the significance level, α.
Step 3: Calculate the appropriate test statistic.
Step 4: Determine the appropriate critical value.
Step 5: Compare the z test statistic,
z
p
, with the critical z-score,
z
a
/
2
.
Step 6: Calculate the p value.
Step 7: State your conclusions.
Excel p-value p.475
Formula 10.20 Approximate Standard Error for the Difference between population proportions p.471:
^
σ
p
1
−
p
2
=
√
´
p
1
(
1
−´
p
1
)
n
1
+
´
p
2
(
1
−´
p
2
)
n
2
´
p
1

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- Spring '13
- Tyler
- Statistics, Statistical hypothesis testing