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Finding the Fourth Proportional to 684.54, 1,024.36 and 638.78

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Solution

The fourth proportional to 684.54, 1,024.36 and 638.78 is: 955.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    684.54 : 1,024.36 = 638.78 : x
  2. Step 2: Convert to fraction form
    684.54/1,024.36 = 638.78/x
  3. Step 3: Cross multiply
    684.54x = 1,024.36 × 638.78
  4. Step 4: Simplify right side
    684.54x = 654,340.68
  5. Step 5: Solve for x
    x = 654,340.68/684.54
  6. Step 6: Final answer
    x = 955.88

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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.