Question

Jana, a high school principal, hosted a movie event at her school. Jana's assistant kept track of the number of students in each grade who attended the event. The distribution shown in the table

represents the number of students in each grade that were present.
Grade Level
Sophomore-56
Senior-70
Freshman-52
Junior-60
Jana knows that the grade levels are equally distributed across the school of 1,200 students. She would like to use a chi-square test to see if the proportion of individuals in each class at the
movie are also equally distributed. How many seniors would be expected at the event?

Answer 1

59.5 Seniors expected

Explanation:

"Equally distributed" means that it is expected that each grade has equal number of students for 1200 schools. This means 1200/4 = 300 students expected in each grade for 1200 students. The proportion would be 300/1200 = .25

The actual total of the school shown is (56+70+52+60) = 238

Therefore 238 * .25 = 59.5 expected students in each grade for this school

The proportion for each grade can also be found by just knowing that each grade has the same proportion.There are 4 grades so 1/4 = .25