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Finding the Fourth Proportional to 402.20, 555.02 and 225.15

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Solution

The fourth proportional to 402.20, 555.02 and 225.15 is: 310.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    402.20 : 555.02 = 225.15 : x
  2. Step 2: Convert to fraction form
    402.20/555.02 = 225.15/x
  3. Step 3: Cross multiply
    402.20x = 555.02 × 225.15
  4. Step 4: Simplify right side
    402.20x = 124,961.63
  5. Step 5: Solve for x
    x = 124,961.63/402.20
  6. Step 6: Final answer
    x = 310.70

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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.