Question

Makenzie wanted to know if students who had cell phones also tend to have laptops. She took a survey and part of the results are shown in the

frequency table below.
Use addition and subtraction to determine each missing value to complete the table.

Answer 1

The missing values added to complete the table:

__________Laptop _ No Laptop _ Total

Cell phone ___57 _____ 21 ______ 78

No cell phone _13 ______9 ______ 22

TOTAL ______70 _____ 30 _____ 100

From the table we can use addition and subtraction operation to deduce the missing values:

LAPTOP Total :

• Cellphone + No Cellphone
• 57 + 13 = 70

NO CELL PHONE Total:

• Total n Total - Cell phone Total
• 100 - 78 = 22

No LAPTOP n No CELLPHONE

• (No Cellphone n Total) - (No Cellphone n Laptop)
• = 22 - 13 = 9

NO Laptop n Total

• (Cellphone n No laptop) + (No Cellphone n No laptop)
• = 21 + 9 = 30

Hence, The complete Table is :

__________Laptop _ No Laptop _ Total

Cell phone ___57 _____ 21 ______ 78

No cell phone _13 ______9 ______ 22

TOTAL ______70 _____ 30 _____ 100