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Finding the Fourth Proportional to 399.12, 551.04 and 288.96

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Solution

The fourth proportional to 399.12, 551.04 and 288.96 is: 398.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.12 : 551.04 = 288.96 : x
  2. Step 2: Convert to fraction form
    399.12/551.04 = 288.96/x
  3. Step 3: Cross multiply
    399.12x = 551.04 × 288.96
  4. Step 4: Simplify right side
    399.12x = 159,228.52
  5. Step 5: Solve for x
    x = 159,228.52/399.12
  6. Step 6: Final answer
    x = 398.95

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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.