A political pollster is conducting an analysis of sample results in order to mak
ID: 3206192 • Letter: A
Question
A political pollster is conducting an analysis of sample results in order to make predictions on election night. Assuming a two-candidate election, if a specific candidate receives at least 53 % of the vote in the sample, that candidate will be forecast as the winner of the election. You select a random sample of 100 voters
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What is the probability that a candidate will be forecast as the winner when the population percentage of her vote is 57%?
**If there is a function in Excel that can help solve this problem, please show using using Excel.
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What is the probability that a candidate will be forecast as the winner when the population percentage of her vote is 57%?
**If there is a function in Excel that can help solve this problem, please show using using Excel.
Explanation / Answer
Normal Distribution
Proportion ( P ) =0.57
Standard Deviation ( sd )= Sqrt (P*Q /n) = Sqrt(0.57*0.43/100)
Normal Distribution = Z= X- u / sd ~ N(0,1)
P(X >= 0.53) = (0.53-0.57)/0.0495
= -0.04/0.0495 = -0.8081
= P ( Z >-0.808) From Standard Normal Table
= 0.7905