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Finding the Fourth Proportional to 284.40, 391.92 and 196.80

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Solution

The fourth proportional to 284.40, 391.92 and 196.80 is: 271.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    284.40 : 391.92 = 196.80 : x
  2. Step 2: Convert to fraction form
    284.40/391.92 = 196.80/x
  3. Step 3: Cross multiply
    284.40x = 391.92 × 196.80
  4. Step 4: Simplify right side
    284.40x = 77,129.86
  5. Step 5: Solve for x
    x = 77,129.86/284.40
  6. Step 6: Final answer
    x = 271.20

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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.