Map Scale Problem: Wisconsin Length Calculation

The source contains a calculation error. Let's solve correctly:

Given

• Map scale: 12 inches = 100 miles
• Wisconsin map length: 1 5/16 inches = 1.3125 inches

Correct Proportion

(Map distance) / (Actual distance) = (Map scale)

1.3125 inches / Actual distance = 12 inches / 100 miles

Cross-Multiply

1.3125 × 100 = 12 × Actual distance

131.25 = 12 × Actual distance

Solve

Actual distance = 131.25 / 12 = 10.9375 miles

Reality Check

This is wrong for actual Wisconsin. Wisconsin's north-south extent is ~310 miles (470 km). The map scale or measured length must be different:

• If scale is 12 inches = 100 miles, Wisconsin should measure ~37 inches on map.
• If Wisconsin measures 1.3125 inches, scale would be ~1 inch = 236 miles.

Lesson

Always verify map scale against known distances. The exercise demonstrates proportion method, but real maps use representative fractions (1:2,500,000) or bar scales for accuracy.