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Finding the Fourth Proportional to 540.78, 811.31 and 280.70

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Solution

The fourth proportional to 540.78, 811.31 and 280.70 is: 421.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    540.78 : 811.31 = 280.70 : x
  2. Step 2: Convert to fraction form
    540.78/811.31 = 280.70/x
  3. Step 3: Cross multiply
    540.78x = 811.31 × 280.70
  4. Step 4: Simplify right side
    540.78x = 227,729.26
  5. Step 5: Solve for x
    x = 227,729.26/540.78
  6. Step 6: Final answer
    x = 421.11

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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.