Answer:
(a)
[tex]P=0.7N+2.2[/tex]
(b)
the price of 50 cloud markers is $37.2
Step-by-step explanation:
(a)
Let's assume
price is P
number of markers is N
We are given
The price of a box of 15 cloud markers is $12.70
so, [tex]N_1=15,P_1=12.70[/tex]
The price of a box of 42 cloud markers is $31.60
so, [tex]N_2=42,P_2=31.60[/tex]
Firstly, we will find slope
[tex]m=\frac{P_2-P_1}{N_2-N_1}[/tex]
now, we can plug values
[tex]m=\frac{31.60-12.70}{42-15}[/tex]
[tex]m=0.7[/tex]
now, we can use point slope form of line
[tex]P-P_1=m(N-N_1)[/tex]
we can plug value
[tex]P-12.70=0.7(N-15)[/tex]
now, we can solve for P
[tex]P-12.70=0.7N-10.5[/tex]
add both sides by 12.70
[tex]P-12.70+12.70=0.7N-10.5+12.70[/tex]
[tex]P=0.7N+2.2[/tex]
(b)
now, we can plug N=50
[tex]P=0.7\times 50+2.2[/tex]
[tex]P=37.2[/tex]
So,
the price of 50 cloud markers is $37.2