Okay. So to find the percentage rate of markup from 1948 to 1967, we can write and solve a proportion. It would be set up like this: change/original = x/100. This means put the distance between two numbers and put it over the initial amount. We'll do this step by step. First off, we'll find the total overall cost. In 1948, it costed $124 dolalrs per acre. 124 * 66 is 8,184. In 1967, it costed $15,787.25 per acre. Multiply that number by 66 to get 1,041,958.5. Let's subtract the total prices. 1,041,958.5 - 8184 is 1,033,774.5. We can set up the proportion like this
1,033,774.5/8184 = x/100
$8,184 is the initial price back in 1948, before the other price of $1,033,774.50. Now, what we do is cross multiplt the values. 1,033,774.5 * 100 is 103,377,450. 8,184 * x is 8,184x. We have 103,377,450 = 8,184x. Now, divide each side by 8,184 to isolate the x. 8,184x/8,184 cancels x out. 103,377,450/8,184 is 12,631.65323 or 12,631.7 when rounded to the nearest tenth. There. The percent rate of markup from 1948 to 1967 is approx. 12,631.7%