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Finding the Fourth Proportional to 280.70, 420.92 and 98.09

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Solution

The fourth proportional to 280.70, 420.92 and 98.09 is: 147.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.70 : 420.92 = 98.09 : x
  2. Step 2: Convert to fraction form
    280.70/420.92 = 98.09/x
  3. Step 3: Cross multiply
    280.70x = 420.92 × 98.09
  4. Step 4: Simplify right side
    280.70x = 41,287.55
  5. Step 5: Solve for x
    x = 41,287.55/280.70
  6. Step 6: Final answer
    x = 147.09

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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.