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Finding the Fourth Proportional to 520.20, 780.30 and 456.20

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Solution

The fourth proportional to 520.20, 780.30 and 456.20 is: 684.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.20 : 780.30 = 456.20 : x
  2. Step 2: Convert to fraction form
    520.20/780.30 = 456.20/x
  3. Step 3: Cross multiply
    520.20x = 780.30 × 456.20
  4. Step 4: Simplify right side
    520.20x = 355,972.86
  5. Step 5: Solve for x
    x = 355,972.86/520.20
  6. Step 6: Final answer
    x = 684.30

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.