Ivy randomly surveys students in her school to learn about mobile phone password use. Of 25 respondents, 14 use a password. Part A
Based on Ivy's data, how many of the 275 students in her school would be expected to use a password?

Part B
If Ivy conducted her survey of 25 students on a volunteer basis, are the results
representative of the school?
Why or why not?

20

step-by-step explanation:

the direct variation says that:

then the equation is of the form is given by:

            where k is the constant variation.

from the given table:

consider any value of x and m(x)=y

x = 2 and m(x)=y = 3

substitute these value in [1]; we have;

divide both sides by 2 we get;

⇒

check:

put x = -1 and m(x) = -1.5

substitute in the equation:

-1.5 = -1.5                   true

therefore, the function m(x) represents a direct variation

graph of this function as shown below: