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Finding the Fourth Proportional to 520.11, 780.51 and 478.40

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Solution

The fourth proportional to 520.11, 780.51 and 478.40 is: 717.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.11 : 780.51 = 478.40 : x
  2. Step 2: Convert to fraction form
    520.11/780.51 = 478.40/x
  3. Step 3: Cross multiply
    520.11x = 780.51 × 478.40
  4. Step 4: Simplify right side
    520.11x = 373,392.08
  5. Step 5: Solve for x
    x = 373,392.08/520.11
  6. Step 6: Final answer
    x = 717.91

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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.