Question:
Solution:
Step 1: Calculate the number of students that touch screen phone in a sample of 816 students:
Let's denote by x the number of students that touch screen phone and consider the following diagram :
By cross-multiplication, solve for x:
[tex]x\text{ = }\frac{(816)(18)}{24}=612[/tex]
Step 2: Subtract the obtained value of step 1 to 816
[tex]816-612\text{ = 204}[/tex]
then, we can conclude that 204 students do not have a touch screen phone.
