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Finding the Fourth Proportional to 280.05, 420.12 and 87.63

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Solution

The fourth proportional to 280.05, 420.12 and 87.63 is: 131.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.05 : 420.12 = 87.63 : x
  2. Step 2: Convert to fraction form
    280.05/420.12 = 87.63/x
  3. Step 3: Cross multiply
    280.05x = 420.12 × 87.63
  4. Step 4: Simplify right side
    280.05x = 36,812.58
  5. Step 5: Solve for x
    x = 36,812.58/280.05
  6. Step 6: Final answer
    x = 131.45

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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.