Reference no: EM132367811 , Length: word count:150
Assignment -
Read the scenario and interpret/explain the results! Min 150 words.
Practice problem: The One-Way ANOVA
A babysitter once told me that she thought regular babysitting was the best contraceptive in the world. She loved kids and planned to have several someday, but she realized how much responsibility they were and was not going to rush into it. I decided to conduct a study to see if babysitting had any impact on the age at which women had their first child. I found 10 women who had never babysat, 10 who babysat occasionally, and 10 who were frequent babysitters. All participants were college graduates. For each, I determined her age at the birth of her first child. The means for the three groups are: never babysat = 23.10 years old at birth of first child; occasional = 24.60; frequent = 26.90.
Below is the ANOVA summary table:
|
Source of Variability
|
Sum of Squares
|
Degrees of Freedom
|
Mean Square
|
F ratio
|
|
Between groups
|
73.27
|
2
|
36.64
|
8.48
|
|
Within groups
|
116.66
|
27
|
4.32
|
|
|
Total
|
189.93
|
29
|
|
|
Interpret the results.
The critical value for the F statistic is 3.35:
HSD = 3.53√(4.3210) = 2.32
Groups 1 and 2 differ by 1.5 years, and this is not a statistically significant difference.
Groups 1 and 3 differ by 3.8 years, and this is a statistically significant difference.
Groups 2 and 3 differ by 2.3 years, and this is a statistically significant difference. r2 = 39%.
I compared the age at which women had their first child depending on whether they had previously been frequent or regular babysitters, or not babysitters at all. The effect was strong and statistically significant-being a regular babysitter was associated with waiting longer to bear a child. This study suggests that regular babysitting functions as a sort of contraceptive. But, please, to draw a cause-and-effect conclusion, young women would have to be assigned to do different amounts of babysitting.
References - Corty, E. (2016). Using and interpreting statistics: A practical text for the behavioral, social, and health sciences (3rd ed.). New York, NY: Macmillan Learning. ISBN-13: 9781464107795 (Corty, 2016, p. 476).
Note - Please try to answer in plain, simple English and rarely use fancy words, you know the average American is not like British English. Thank you.