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Finding the Fourth Proportional to 402.78, 556.02 and 315.30

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Solution

The fourth proportional to 402.78, 556.02 and 315.30 is: 435.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    402.78 : 556.02 = 315.30 : x
  2. Step 2: Convert to fraction form
    402.78/556.02 = 315.30/x
  3. Step 3: Cross multiply
    402.78x = 556.02 × 315.30
  4. Step 4: Simplify right side
    402.78x = 175,313.11
  5. Step 5: Solve for x
    x = 175,313.11/402.78
  6. Step 6: Final answer
    x = 435.26

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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.