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Finding the Fourth Proportional to 811.80, 1,120.20 and 480.24

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Solution

The fourth proportional to 811.80, 1,120.20 and 480.24 is: 662.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.80 : 1,120.20 = 480.24 : x
  2. Step 2: Convert to fraction form
    811.80/1,120.20 = 480.24/x
  3. Step 3: Cross multiply
    811.80x = 1,120.20 × 480.24
  4. Step 4: Simplify right side
    811.80x = 537,964.85
  5. Step 5: Solve for x
    x = 537,964.85/811.80
  6. Step 6: Final answer
    x = 662.68

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Double scale
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.