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Finding the Fourth Proportional to 284.64, 426.40 and 212.80

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Solution

The fourth proportional to 284.64, 426.40 and 212.80 is: 318.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    284.64 : 426.40 = 212.80 : x
  2. Step 2: Convert to fraction form
    284.64/426.40 = 212.80/x
  3. Step 3: Cross multiply
    284.64x = 426.40 × 212.80
  4. Step 4: Simplify right side
    284.64x = 90,737.92
  5. Step 5: Solve for x
    x = 90,737.92/284.64
  6. Step 6: Final answer
    x = 318.78

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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.