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Finding the Fourth Proportional to 402.31, 603.40 and 128.34

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Solution

The fourth proportional to 402.31, 603.40 and 128.34 is: 192.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    402.31 : 603.40 = 128.34 : x
  2. Step 2: Convert to fraction form
    402.31/603.40 = 128.34/x
  3. Step 3: Cross multiply
    402.31x = 603.40 × 128.34
  4. Step 4: Simplify right side
    402.31x = 77,440.04
  5. Step 5: Solve for x
    x = 77,440.04/402.31
  6. Step 6: Final answer
    x = 192.49

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.