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Finding the Fourth Proportional to 402.90, 604.40 and 128.93

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Solution

The fourth proportional to 402.90, 604.40 and 128.93 is: 193.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    402.90 : 604.40 = 128.93 : x
  2. Step 2: Convert to fraction form
    402.90/604.40 = 128.93/x
  3. Step 3: Cross multiply
    402.90x = 604.40 × 128.93
  4. Step 4: Simplify right side
    402.90x = 77,921.63
  5. Step 5: Solve for x
    x = 77,921.63/402.90
  6. Step 6: Final answer
    x = 193.40

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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.