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Finding the Fourth Proportional to 742.20, 1,023.39 and 648.78

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Solution

The fourth proportional to 742.20, 1,023.39 and 648.78 is: 894.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    742.20 : 1,023.39 = 648.78 : x
  2. Step 2: Convert to fraction form
    742.20/1,023.39 = 648.78/x
  3. Step 3: Cross multiply
    742.20x = 1,023.39 × 648.78
  4. Step 4: Simplify right side
    742.20x = 663,954.96
  5. Step 5: Solve for x
    x = 663,954.96/742.20
  6. Step 6: Final answer
    x = 894.58

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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.