A sample of 60 students were taken.
Out of which only 15 said that they will vote for Madelyn.
There are 140 7-th grade students.
Based on the sample data, we want to know how many might vote for Madelyn.
Well, it's quite simple.
15 out of 60 will vote for Madelyn
That is:
So, 1/4th of total students will vote for Madelyn.
That is:
Based on the sample data, 35 people are expected to vote for Madelyn [out of total of 140 people].