Let’s solve each question step by step using the dot plot.
First, let’s count how many dots are above each number on the number line (time in minutes):
- 1 minute: 1 dot → 1 student
- 2 minutes: 2 dots → 2 students
- 3 minutes: 1 dot → 1 student
- 4 minutes: 3 dots → 3 students
- 5 minutes: 1 dot → 1 student
- 6 minutes: 4 dots → 4 students
- 7 minutes: 0 dots → 0 students
- 8 minutes: 2 dots → 2 students
- 9 minutes: 3 dots → 3 students
- 10 minutes: 2 dots → 2 students
Total students = 1 + 2 + 1 + 3 + 1 + 4 + 0 + 2 + 3 + 2 =
19 students
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Question 1: How many students took 8 or more minutes to eat their lunch?
“8 or more” means 8, 9, and 10 minutes.
- 8 minutes: 2 students
- 9 minutes: 3 students
- 10 minutes: 2 students
Add them: 2 + 3 + 2 =
7 students
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Question 2: What percentage of students ate their lunch in 5 minutes or less?
“5 minutes or less” means 1, 2, 3, 4, and 5 minutes.
- 1 min: 1
- 2 min: 2
- 3 min: 1
- 4 min: 3
- 5 min: 1
Add them: 1 + 2 + 1 + 3 + 1 =
8 students
Total students = 19
Percentage = (8 ÷ 19) × 100 ≈ ?
Let’s calculate:
8 ÷ 19 = 0.42105...
Multiply by 100 → 42.105...%
We can round to the nearest whole percent:
42%
(If your teacher wants one decimal place, it’s 42.1%, but since no instruction is given, 42% is fine.)
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Question 3: What is the average time it takes this group of students to eat their lunch?
Average = total time for all students ÷ number of students
We need to multiply each time by how many students took that long, then add them up.
Let’s do it:
- 1 min × 1 student = 1
- 2 min × 2 students = 4
- 3 min × 1 student = 3
- 4 min × 3 students = 12
- 5 min × 1 student = 5
- 6 min × 4 students = 24
- 7 min × 0 students = 0
- 8 min × 2 students = 16
- 9 min × 3 students = 27
- 10 min × 2 students = 20
Now add all these products:
1 + 4 = 5
5 + 3 = 8
8 + 12 = 20
20 + 5 = 25
25 + 24 = 49
49 + 0 = 49
49 + 16 = 65
65 + 27 = 92
92 + 20 =
112
Total time = 112 minutes
Number of students = 19
Average = 112 ÷ 19
Let’s divide:
19 × 5 = 95
112 - 95 = 17 → so 5 and 17/19
As a decimal: 112 ÷ 19 ≈ 5.8947...
Rounded to two decimal places:
5.89 minutes
(You could also leave it as a mixed number: 5 17/19 minutes, but decimals are usually expected for averages unless told otherwise.)
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Final Answer:
1. 7 students
2. 42%
3. 5.89 minutes
Parent Tip: Review the logic above to help your child master the concept of dot plot worksheet.
