Median
8, 12, 15, 20, 25
Answer: 15
(1 middle number)
15, 5, 20, 10
Answer: 12.5
(15 + 5 + 20 + 10 = 50 ÷ 4 = 12.5)
Find the LCM of:
6 and 8
Answer: 24
Find Q2 (Median):
14, 6, 10, 18, 22
Answer: 14
Ordered: 6, 10, 14, 18, 22
Q2 = 14
The ________ is found by adding all the numbers together and dividing by how many numbers there are.
Answer: mean (or average)
14, 6, 18, 10
Answer: 12
(Ordered: 6, 10, 14, 18
(10 + 14) ÷ 2 = 12 → 2 middle numbers)
A student scored these points:
18, 12, 24, 6
Answer: 15
(18 + 12 + 24 + 6 = 60 ÷ 4 = 15)
Find the GCF of:
18 and 24
Answer: 6
Find Q1:
20, 4, 12, 8, 16, 24, 28
Answer: 8
Ordered: 4, 8, 12, 16, 20, 24, 28
Lower half: 4, 8, 12
Q1 = 8
True or False: The median is the middle number in an ordered data set.
Answer: True
A group of students scored these points:13, 9, 17, 11, 15 What's the middle score?
Answer: 13
(Ordered: 9, 11, 13, 15, 17 → 1 middle number)
Number of minutes students read:
25, 15, 20, 10, 30 What is the mean time?
Answer: 20
(25 + 15 + 20 + 10 + 30 = 100 ÷ 5 = 20)
Find the LCM of:
9 and 12
Answer: 36
Find Q3:
11, 27, 15, 23, 7, 19, 31
Answer: 27
Ordered: 7, 11, 15, 19, 23, 27, 31
Upper half: 23, 27, 31
Q3 = 27
“I am the middle number in an ordered data set. What am I?”
Answer: Median
Test scores: 85, 70, 80, 75 What is the median?
Answer: 77.5
(Ordered: 70, 75, 80, 85 → (75 + 80) ÷ 2 = 77.5 → 2 middle numbers)
Find the mean:
32, 24, 16, 28, 20, 10
Answer: 21.7
(32 + 24 + 16 + 28 + 20 + 10 = 130 ÷ 6 = 21.7)
Find the GCF of:
20 and 30
Answer: 10
Min = 4, Q1 = 10, Median (Q2) = 15, Q3 = 22, Max = 30 What is the interquartile range (IQR)?
Answer: 12
IQR = Q3 − Q1
22 − 10 = 12
Mean, GCF, Median, IQR
Which one does NOT belong?
Answer: GCF
(Mean, median, and IQR are all related to data/statistics. GCF is factors/multiples.)
Heights of plants (in inches):22, 12, 18, 14, 20, 16 What is the median height?
Answer: 17
(Ordered: 12, 14, 16, 18, 20, 22 → (16 + 18) ÷ 2 = 17 → 2 middle numbers)
A class recorded these test scores:
95, 70, 85, 60, 90, 80, 75
What is the mean score?
Answer: 79.3
(95 + 70 + 85 + 60 + 90 + 80 + 75 = 555 ÷ 7 = 79.3)
Find the GCF and LCM of:
12 and 18
Answer: GCF = 6 and LCM = 36
Find the min, Q1, median (Q2), Q3, and max:
18, 10, 25, 14, 30, 22, 16
Ordered: 10, 14, 16, 18, 22, 25, 30
Min = 10
Q1 = 14
Q2 (Median) = 18
Q3 = 25
Max = 30
A student says: “To find the IQR, subtract the minimum from the maximum.” What is the mistake?
Answer: IQR is found by subtracting Q1 from Q3, not minimum from maximum.