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Finding the Fourth Proportional to 280.56, 420.80 and 126.66

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Solution

The fourth proportional to 280.56, 420.80 and 126.66 is: 189.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.56 : 420.80 = 126.66 : x
  2. Step 2: Convert to fraction form
    280.56/420.80 = 126.66/x
  3. Step 3: Cross multiply
    280.56x = 420.80 × 126.66
  4. Step 4: Simplify right side
    280.56x = 53,298.53
  5. Step 5: Solve for x
    x = 53,298.53/280.56
  6. Step 6: Final answer
    x = 189.97

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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.