Question

from unit 1, lesson 2
the dot plot displays the lengths of pencils (in inches) used by students in a class. what is
the mean?
dot plot with 5 (1 dot), 5.5 (2 dots), 6 (4 dots), 6.5 (2 dots), 7 (1 dot) on the number line labeled length (inches)

Explanation:

Step1: Count the number of dots for each length

• For length 5: 1 dot, so total length contribution is \(5\times1 = 5\)
• For length 5.5: 2 dots, so total length contribution is \(5.5\times2 = 11\)
• For length 6: 4 dots, so total length contribution is \(6\times4 = 24\)
• For length 6.5: 2 dots, so total length contribution is \(6.5\times2 = 13\)
• For length 7: 1 dot, so total length contribution is \(7\times1 = 7\)

Step2: Calculate the total sum of lengths

Sum all the contributions: \(5 + 11 + 24 + 13 + 7 = 60\)

Step3: Calculate the total number of dots (total number of pencils)

Total dots: \(1 + 2 + 4 + 2 + 1 = 10\)

Step4: Calculate the mean

Mean is total sum divided by total number of data points: \(\frac{60}{10} = 6\)

Answer:

6