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Finding the Fourth Proportional to 520.32, 780.48 and 135.57

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Solution

The fourth proportional to 520.32, 780.48 and 135.57 is: 203.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.32 : 780.48 = 135.57 : x
  2. Step 2: Convert to fraction form
    520.32/780.48 = 135.57/x
  3. Step 3: Cross multiply
    520.32x = 780.48 × 135.57
  4. Step 4: Simplify right side
    520.32x = 105,809.67
  5. Step 5: Solve for x
    x = 105,809.67/520.32
  6. Step 6: Final answer
    x = 203.36

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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.