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Finding the Fourth Proportional to 478.17, 660.28 and 399.91

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Solution

The fourth proportional to 478.17, 660.28 and 399.91 is: 552.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    478.17 : 660.28 = 399.91 : x
  2. Step 2: Convert to fraction form
    478.17/660.28 = 399.91/x
  3. Step 3: Cross multiply
    478.17x = 660.28 × 399.91
  4. Step 4: Simplify right side
    478.17x = 264,049.92
  5. Step 5: Solve for x
    x = 264,049.92/478.17
  6. Step 6: Final answer
    x = 552.21

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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.