statistics

1. Math assignment- statistics By Maggie & Jade

2. Our investigation question Do female sibling numbers tend to be larger than males sibling numbers on average of adults in America(over18) from the GSS?

3. Summary statistics

4. Box and whisker plot

5. I notice…… • The difference between the medians of female and males sample is 1 sibling, which means that on average female tend to have 1 more sibling than male back in the population. • The median(3 siblings) and the upper quartile(5 siblings) of female on average are larger than males plot, which indicates that female may tend to have more siblings than males on average. • Female's box plot is more positively skewed due to extreme values at 12 siblings, I believe that this is extreme as there is a gap between this value and the next which is 11 siblings. where as the male sample is more symmetrical. • The minimum value (1 sibling) for the females is the same as its lower quartile (1 sibling). • The male box plot is overlapped by the female box plot from 1 sibling to 4 siblings) • The lower quartile for both female and male are the same (1 sibling).

6. I notice…… The female data is flatter and more evenly spread than the male data. This indicates that the number of siblings of female is more variable than females. The female's have a bigger range than males, starting at 1 sibling and ending at 12 siblings vs. males starting at 0 sibling to 8 sibling. Indicate that female have more variation in amount of siblings they have and males are more consistent. There are clusters around 1 to 5 siblings for the female dot plot. There are clusters around 0 to 4 siblings for the male dot plot. There is a large peak at 1 sibling for the females dot plot, where 8 females have 1 sibling. That the range of the middle 50% for females is larger than males (4 siblings vs. 3 siblings) indicating that females sibling number are more varied and males are more consistent.

7. Conclusion In conclusion the 1/3 rule does not apply to this sample due to the minimum and lower quartile are the same(1 sibling) for female and also the males lower quartile is the same as females lower quartile at 1 sibling. However the ¾-1/2 rule does not apply either because the median difference( 1 sibling ) is not at least 1/3 of the overall visible spread(4 siblings). Therefore I am not very confident in my call that female tend to have larger sibling numbers than males in America back in the populations .

8. Sampling variability We are not very confident that females tend to have more siblings than males back in the population, but if we take more examples, we would expect the characteristics of the samples to be different but that I would still be able to make the call that females tends to have more siblings than males of adults over 18 in America from the GSS.

9. Inference We expected to find that females tend to have more siblings than males in America back in the population, I think this make sense because the population of males in America is about 152 million, where as female population is 156.8 million, so there are more females in America which means there is a greater chance that people has siblings that are females, so female has more sibling numbers than males back in the population.