In 1957 the price of a McDonald’s hamburger was 43¢. In 2002, the price of a hamburger was 88¢. Assuming the price increased linearly, what was the price of a McDonald’s hamburger in 1971?

Question

In 1957 the price of a McDonald’s hamburger was 43¢.  In 2002, the price of a hamburger was 88¢.  Assuming the price increased linearly, what was the price of a McDonald’s hamburger in 1971?

anonymous · Answer

help?

anonymous · Answer

ok we can do this

anonymous · Answer

idea is to find the equation of the line between two points
 $(1957,43)$ and $(2002,83)$

anonymous · Answer

ok

anonymous · Answer

first we find the slope, which is 
$$\frac{83-43}{2002-1957}=\frac{40}{45}=\frac{8}{9}$$

shane_b · Answer

The slope will be 1...I think you used the wrong 2002 value :)

anonymous · Answer

caught me!

anonymous · Answer

$$\frac{88-43}{2002-1957}=\frac{45}{45}=1$$

anonymous · Answer

in other words the burger increases by a penny a year

anonymous · Answer

1971 is 14 years after 1957, so if it goes up a penny a year the price has increased by 14 cents from 43 cents

anonymous · Answer

ok