The prize pretzel company most popular pretzel sells for $4.80 per bag. the table below shows the cost of these pretzels in various years. ¡ assuming the price change at a steady rate, what was the price of the pretzels in 1975?

The price of pretzels in 1975 = $1.80

Step-by-step explanation:

To answer this question we are assuming the steady rate means linear.Let x be the year and y be the price.

We need to find the slope

m = (y2-y1)/(x2-x1)

  = (4.80-4.05)/(2015-2005)

  =.75/10

 = .075

The slope is .075

We can use the point slope form of the equation  

y-y1 = m(x-x1)

y-4.80 = .075(x-2015)

Distribute

y - 4.80 = .075x -151.125

Add 4.80 to each side

y - 4.80+4.80 = .075x -151.125+4.80

y =  .075 x - 146.325

We want to find out how much pretzels were in 1975.  Put in x=1975

y = .075(1975) -146.325

y = 148.125-146.325

y=1.80