Binomial or cumulative distribution.

Wutanerd116

New member
Joined
Feb 10, 2009
Messages
2
"what do you think is the ideal number of children for a family to have?" A gallup poll asked this of 1006 randomly chosen adults. Almost hlaf (49%) thought two children was ideal. Suppose that p= .49 is exactly true for all adults. Let X= number of adults who thought that two children was ideal.

1) Find the mean and standard deviation of X
I know that p=.49 and n=1006 however i do't have the proper formulas cause i keep getting the standard deviation to equal more that one...

2)Find the probability that X=493
I think i use bionomcdf on my calculator but im not sure

3)Find the probability that X is within two standard deviations of the mean.
I have no idea what to do here.

4) Describe the distribution of the bionomial random variable X.
Again no idea.

5) Would it make sese to compare you results in number 3 to the emperical rule? Explain.
What is the emperical rule?
 
Top