Question

Jack and Jill are two students in Mrs.Juliano's math class.On the last five quizzes,Jack scored an 80,90,95,85, and 70. Jill scored a 70,75,90,100, and 95.

Find the median and interquartile range for each student.

Which student's quiz grades are more consistent?

Answer 1

Median = it is the middle value, which split the higher half from the lower half of the data

To find it order the data:

Jack: 70, 80, 85, 90, 95 => median = 85

Jill: 70, 75, 90, 95, 100 => median = 90

Interquartile range, IQR = Percentil 75th - Percentil 25th

Jack:

Percentil 75% = Q3

5 data * 75% = 3.75 => the next value (over the 3rd) is the 4th => Q3 = 90

Percentil 25% = Q1

5 data * 25% = 1.25 => the next value (over the first) is the 2nd => Q1 = 80

Interquartile range = Q3 - Q1 = 90 - 80 = 10

Jill:

Q3 = fourth value = 95
Q1 = second value = 75

IQR = Q3 - Q1 = 95 - 75 = 20