Emma wants to estimate the percentage of people who use public transportation. She surveys 140 individuals and finds that 100 use public transportation. What is the sample proportion for successes,

X=100 number of individuals who use public transportation

n =140 number of people surveyed

The estimated proportion is given by:

And that represent 71.4%

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".  

The margin of error is the range of values below and above the sample statistic in a confidence interval.  

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".  

Solution to the problem

For this case we define:

X=100 number of individuals who use public transportation

n =140 number of people surveyed

The estimated proportion is given by:

And that represent 71.4%

see below

step-by-step explanation:

x+2> 6

subtract 2 from each side

x+2-2 > 6-2

x > 4

there is an open circle at 4 since is it is greater than and the line goes to the right