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Finding the Fourth Proportional to 280.56, 421.61 and 278.13

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Solution

The fourth proportional to 280.56, 421.61 and 278.13 is: 417.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.56 : 421.61 = 278.13 : x
  2. Step 2: Convert to fraction form
    280.56/421.61 = 278.13/x
  3. Step 3: Cross multiply
    280.56x = 421.61 × 278.13
  4. Step 4: Simplify right side
    280.56x = 117,262.58
  5. Step 5: Solve for x
    x = 117,262.58/280.56
  6. Step 6: Final answer
    x = 417.95

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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.