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Finding the Fourth Proportional to 400.72, 553.32 and 318.28

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Solution

The fourth proportional to 400.72, 553.32 and 318.28 is: 439.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    400.72 : 553.32 = 318.28 : x
  2. Step 2: Convert to fraction form
    400.72/553.32 = 318.28/x
  3. Step 3: Cross multiply
    400.72x = 553.32 × 318.28
  4. Step 4: Simplify right side
    400.72x = 176,110.69
  5. Step 5: Solve for x
    x = 176,110.69/400.72
  6. Step 6: Final answer
    x = 439.49

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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.