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Finding the Fourth Proportional to 520.48, 780.66 and 135.72

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Solution

The fourth proportional to 520.48, 780.66 and 135.72 is: 203.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.48 : 780.66 = 135.72 : x
  2. Step 2: Convert to fraction form
    520.48/780.66 = 135.72/x
  3. Step 3: Cross multiply
    520.48x = 780.66 × 135.72
  4. Step 4: Simplify right side
    520.48x = 105,951.18
  5. Step 5: Solve for x
    x = 105,951.18/520.48
  6. Step 6: Final answer
    x = 203.56

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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.