- Florida played a key role in the 2000 and 2004 USA presidential elections. Voter registration records in August 2010 show that 41% of Florida voters are registered as Democrats and 36% as Republicans. (Most of the others did not choose a party.) To test a random digit dialing device that you plan to use to poll voters for the 2010 Senate elections, you use it to call 250 randomly chosen residential telephones in Florida. Of the registered voters contacted, 34% are registered Democrats. Is each of the boldface numbers a parameter or a statistic?
parameter vs population Parameter is population but the statistics of it
statistics vs sample statistics is number of sample
41% is parameter 36% 34%
- Suppose that the distribution of body mass index (BMI) among young women is Normal with mean 27 and standard deviation 7.5. a) You take an sample of 100 young women. According to the 99.7 part of the 68–95– 99.7 rule, about what range of BMI values do you expect to see in your sample?
b) You look at many samples of size 100. About what range of sample mean BMIs do you expect to see?