MATH SOLVE

4 months ago

Q:
# Suppose a candidate for public office is favored by only 48% of the voters. if a sample survey randomly selects 2500 voters, the percentage in the sample who favor the candidate can be thought of as a measurement from a normal curve with a mean of 48% and a standard deviation of 1%. based on this information, how often would such a survey show that 50% or more of the sample favored the candidate?

Accepted Solution

A:

Mean=0.48

standard deviation=0.01

thus using the z-score:

P(x>0.5) we shall have the following:

z=(0.5-0.48)/0.01=2

thus

P(x>0.5)

=1-P(x<0.5)

=1-P(z<2)

=1-0.9772

=0.0228

standard deviation=0.01

thus using the z-score:

P(x>0.5) we shall have the following:

z=(0.5-0.48)/0.01=2

thus

P(x>0.5)

=1-P(x<0.5)

=1-P(z<2)

=1-0.9772

=0.0228