SIMPSON’S PARADOX How does it happen?
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Transcript of SIMPSON’S PARADOX How does it happen?
SIMPSON’S PARADOX
How does it happen?
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Pamela Leutwyler
A perfume company is testing two new scents:
Citrus
And
Orange blossom
28 single women volunteer to test these products
15 are Eagles cheerleaders
13 are members ofGranny’s bingo club
13 women choose CITRUS
15 women choose ORANGE
4 OF THE 5 CHEERLEADERSWHO USED CITRUS FOUND LOVE!
80% success rate
7 OF THE 10 CHEERLEADERSWHO USED ORANGE FOUND LOVE!
70% success rate
CITRUS appears to be more effective for cheerleaders
80% success rate70% success rate
2 OF THE 8 GRANNIESWHO USED CITRUS FOUND LOVE!
1 OF THE 5 GRANNIESWHO USED ORANGE FOUND LOVE!
CITRUS appears to be more effective for grannies
25% success rate 20% success rate
80% success rate70% success rate
25% success rate 20% success rate
CITRUS is better for cheerleaders
CITRUS is better for grannies
6 of the 13 women who usedCitrus found love. 46%
8 of the 15 women who usedOrange found love. 53%
Overall Orange has a higher success rate
How can it happen thatCITRUS works better for cheerleaders and
CITRUS works better for granniesWhile
ORANGE works better overall???
Where are most of the grannies?
Where are most of the cheerleaders?