Question

Mary is saving money for college expenses. She saves the same amount each month. The table shows the amount of money Mary has saved after 4 and 7 months.Number of months:4,7Total amount of savings (dollars):80,140which statements about this situation are true and support the relationship as being proportional?which 2 statements is true? A) a constant of $20 can be multiplied by the number of months to find the amount in the account.B) a constant of $20 can be added to the number of months to find the amount in the account.C) the values of the ratios in the table, total amount of savings to number of months,are equivalent.D) if graphed on the coordinate plane, the values in the table fall on a line that passes through the origin.E) the table of values shows that $60 is added to the account each month.

Answer 1

we know that

A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form y=Kx

where

K is the constant of proportionality or slope of the linear equation

In this problem

x ----> is the number of months

y -----> is the total amount savings

we have the ordered pairs

(4,80) and (7,140)

so

Find the value of K

K=y/x

For (4,80)

K=80/4=20

For (7,140)

K=140/7=20

The value of K is the same for both ordered paits

that means------> is a proportional relationship

therefore

the linear equation is

y=20x

the answer is the option A, C and D