we are given a chart of values and we are told they increase linearly. We will first find the equation for the line that describes the chart. we will find first the slope of the line using the points (1,74) and (2,78), using the following formula

replacing the values

the general equation for the line is

the value b, we find it using the point (1,74), replacing we get


the equation for this line is

Since "x" represents the chore, when we set x = 0 in the equation of the line, we get the value of the savings, that is, y = 70