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Finding the Fourth Proportional to 399.78, 551.67 and 225.12

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Solution

The fourth proportional to 399.78, 551.67 and 225.12 is: 310.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.78 : 551.67 = 225.12 : x
  2. Step 2: Convert to fraction form
    399.78/551.67 = 225.12/x
  3. Step 3: Cross multiply
    399.78x = 551.67 × 225.12
  4. Step 4: Simplify right side
    399.78x = 124,191.95
  5. Step 5: Solve for x
    x = 124,191.95/399.78
  6. Step 6: Final answer
    x = 310.65

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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.