Answer:
1:8,632,800
Explanation:
we have a 4-by-6-inch index card on which the state of Colorado and Wyoming should be drawn, so we must add the areas of the two states and adapt them in scale , for this we must add the width of the two states (within 4 inches) and the length (within 6 inches) of them
According graph:
380 miles+365 miles=745 miles (long)
265 miles+280 miles=545 miles (wide)
if 545 miles ≡ 4 inch
x miles ≡ 1 inch
1 inch ≡ 136.25 miles, but 1 mile ≡ 63,360 inch, so
1 inch (index card) ≡ (63,360 inch * 136.25 miles) = 8,632,800 inch in the reality, then 545 miles = 34,531,200 inch and 745 miles= 47,203,200, inch
This to say that:
34,531,200 inch / 8,632,800 inch/mile = 4 inch
47,203,200 / 8,632,800 inch/mile = 5.46 inch
finally,
the scale is 1:8,632,800 ≡ 1 inch in the index card = 8,632,800 in the reality or 1 inch in the index card = (8,632,800/63360) 136.25 miles in the reality