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Finding the Fourth Proportional to 280.72, 387.20 and 197.68

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Solution

The fourth proportional to 280.72, 387.20 and 197.68 is: 272.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.72 : 387.20 = 197.68 : x
  2. Step 2: Convert to fraction form
    280.72/387.20 = 197.68/x
  3. Step 3: Cross multiply
    280.72x = 387.20 × 197.68
  4. Step 4: Simplify right side
    280.72x = 76,541.70
  5. Step 5: Solve for x
    x = 76,541.70/280.72
  6. Step 6: Final answer
    x = 272.66

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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.