Step 1 :Given the number of students in each age group as follows:
Step 2 :Under 21 years: 420 students
Step 3 :21-25 years: 400 students
Step 4 :26-30 years: 219 students
Step 5 :31-35 years: 56 students
Step 6 :Over 35 years: 24 students
Step 7 :The total number of students is 1,119.
Step 8 :We are asked to find the probability that a randomly selected student is between 26 and 35 years old. This includes the age groups 26-30 and 31-35.
Step 9 :The total number of students between 26 and 35 years old is the sum of the students in the age groups 26-30 and 31-35, which is \(219 + 56 = 275\).
Step 10 :The probability of an event is calculated by dividing the number of ways the event can occur by the total number of outcomes. In this case, the event is a student being between 26 and 35 years old, and the total number of outcomes is the total number of students.
Step 11 :So, the probability is calculated as \( \frac{275}{1119} \approx 0.246 \)
Step 12 :Final Answer: The probability that a randomly selected student is between 26 and 35 years old is approximately \(\boxed{0.246}\).