What is the value of the 3 in 630?

In the football stadium, there are 18 empty seats out of 360 total seats. (1a) write the ratio of empty seats to total seats as a fraction in simplest form. (1b) then explain its meaning.

Iq scores for adults age 20 to 34 years are normally distributed according to n(120, 20). in what range does the middle 68% of people in this group score on the test?

Which of the following is true for the relation f(x)=2x^2+1