1. Hypothesis Testing on Vacation
Time: Aug, 1990
Place: Campground
“Can we buy an RV?”
“Why?”
“Everyone else does!”
“Really!?”

2. Let us collect some data!
My Favorite Recipe :
Question
Data
Analysis
Conclusion

3. Decision Through Data! Question: “Does everyone else have RV’s?”
If p>0.5, we will buy an RV!
Data: To and from Yellowstone, tallied all vehicles in the opposite direction.

4. Hypothesis Testing on Vacation
Original Data Collection Sheets

5. Hypothesis Testing on Vacation
HO: p = 0.5 HA: p < 0.5
Analysis: x = 67 RV’s n = 857 vehicles z = P-value = 0
Conclusion:
There is strong evidence for p<0.5.
Less than 50% people have RV’s!
$ saved!

6. Follow Up Confidence Interval to find the true proportion of RV’s: p = ?
Analysis: x = 67 RV’s n = 857 vehicles We want 95% confidence.
Conclusion:
We are 95% Confident that
the true p = (0.078±0.018)!
Only 6% to 9.6% people have RV’s!
$ saved!