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Finding the Fourth Proportional to 280.18, 420.31 and 87.74

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Solution

The fourth proportional to 280.18, 420.31 and 87.74 is: 131.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.18 : 420.31 = 87.74 : x
  2. Step 2: Convert to fraction form
    280.18/420.31 = 87.74/x
  3. Step 3: Cross multiply
    280.18x = 420.31 × 87.74
  4. Step 4: Simplify right side
    280.18x = 36,878.00
  5. Step 5: Solve for x
    x = 36,878.00/280.18
  6. Step 6: Final answer
    x = 131.62

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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.