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Finding the Fourth Proportional to 681.20, 1,020.18 and 392.12

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Solution

The fourth proportional to 681.20, 1,020.18 and 392.12 is: 587.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.20 : 1,020.18 = 392.12 : x
  2. Step 2: Convert to fraction form
    681.20/1,020.18 = 392.12/x
  3. Step 3: Cross multiply
    681.20x = 1,020.18 × 392.12
  4. Step 4: Simplify right side
    681.20x = 400,032.98
  5. Step 5: Solve for x
    x = 400,032.98/681.20
  6. Step 6: Final answer
    x = 587.25

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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.