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Finding the Fourth Proportional to 520.53, 780.80 and 135.78

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Solution

The fourth proportional to 520.53, 780.80 and 135.78 is: 203.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.53 : 780.80 = 135.78 : x
  2. Step 2: Convert to fraction form
    520.53/780.80 = 135.78/x
  3. Step 3: Cross multiply
    520.53x = 780.80 × 135.78
  4. Step 4: Simplify right side
    520.53x = 106,017.02
  5. Step 5: Solve for x
    x = 106,017.02/520.53
  6. Step 6: Final answer
    x = 203.67

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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.