Test 1
Ho - rbr is made up of equal numbers of open category riders (under 35)
and masters riders (35 and over).
Ha - rbr is made up of mostly masters riders (35 or over).
Volunteers
Open catergory (under 35) = 0
Masters (35 and over) = 13.
This was almost a no brainer; the probability of getting 13 out of 13
masters riders if the population proportion is 50% is .5^13 = .0001.
This is statistically significant so we can reject the null (duhhhhh).We
would need a masters proportion of .8 for this not to be statistically
significant.
Conclusion: At the 95% confidence level, we can say that rbr is made up
of at least 80% masters.
There are a couple of masters who ride open category but my
determination is age based.
Test 2
Ho - there is no difference in the mean weight of rbr open category
riders (under 35) compared to rbr masters (35 or over).
Ha - rbr masters (35 and over) are significantly heavier than rbr open
category riders (under 35).
I'm 10 open category riders short of conducting this test, however, here
are the stats on the volunteers who did submit their data.
Weight(lb) Max=216, min=129, mean=167, sd=21.35
Height(in) Max=75, min=66, mean=70.65, sd=2.78
I did omit one outlier from the data. Comparing these stats to the
general population, they are in the 25th to 30th percentile of weight
and not statistically different in height. A best fit regression of
weight versus height came up with weight = .0714height^1.82 (r=.57) and
weight = -154.28+4.5473height (r=.59). Omitting the data point with the
largest residual resulted in weight =.0016height^2.7 (r=.73).
Thanks to those who sent in their data.
Phil H