In a certain large metropolitan city there are two candidates running for Mayor,
ID: 3152222 • Letter: I
Question
In a certain large metropolitan city there are two candidates running for Mayor, Ronald Chump and Haile Minton. 48% of the voters are in favor of Ms. Minton. An exit poll (this is a random sample taken of people exiting polling place) of 3600 people was taken. X = the number of people who voted for Ms. Minton. What is the mean of X? mu_X = What is the standard deviation of X? sigma_x = (Round to 2 decimal places) Using the Normal Approximation to Binomial, what is the probability that more than 1805 people voted for Ms. Minton?Explanation / Answer
A)The mean of X is: x=n*p=3600*0.48=1728
B)The standard deviation of X is: x=root over np(1-p)
=root over 1728(1-0.48)
=29.97
C)Use Normal approximation to Binomial to find:
P(X>1805)
For X=1805, z=(X-mu)/sigma
=(1805-1728)/29.97
=2.57
Thus P(X>1805)=P(z>2.57)=1-0.9949=0.0051