Question 563573
When a bucket is filled 3/8 of its capacity its weight is 10 kg.
 If it is filled 3/5 of its capacity its weight is 14.5 kg.
 How much will its weight be when it is filled to the full capacity?
:
We can convert these fractions to exact decimals
{{{3/8}}} = .375
{{{3/5}}} = .6
:
Assign the values as follows
x1 = .375; y1 = 10
x2 = .600; y2 = 14.5
:
Find the slope m = {{{(y2-y1)/(x2-x1)}}}
m = {{{(14.5-10)/(.6-.375)}}} = {{{4.5/.225}}} = 20
:
Use the point/slope form to construct an equation: y - y1 = m(x - x1)
y - 10 = 20(x - .375)
y - 10 = 20x - 7.5
y = 20x - 7.5 + 10
y = 20x + 2.5, is the equation
:
Bucket is full when x = 1
y = 20(1) + 2.5
y = 22.5 kg for a full bucket