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Finding the Fourth Proportional to 280.80, 387.60 and 247.68

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Solution

The fourth proportional to 280.80, 387.60 and 247.68 is: 341.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.80 : 387.60 = 247.68 : x
  2. Step 2: Convert to fraction form
    280.80/387.60 = 247.68/x
  3. Step 3: Cross multiply
    280.80x = 387.60 × 247.68
  4. Step 4: Simplify right side
    280.80x = 96,000.77
  5. Step 5: Solve for x
    x = 96,000.77/280.80
  6. Step 6: Final answer
    x = 341.88

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.