In exercises 1 - 3, a survey of 2100 students reported that 315 prefer having gym class during the last period of class. 1. What percent of students prefer having a gym during the last period of the day?

2. What is the margin of sampling error? Round your answer to the nearest tenth of a percent.

3. Give an interval that is likely to contain the exact present of all students who prefer to have gym class during the last period.