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Finding the Fourth Proportional to 681.10, 1,020.83 and 420.69

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Solution

The fourth proportional to 681.10, 1,020.83 and 420.69 is: 630.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.10 : 1,020.83 = 420.69 : x
  2. Step 2: Convert to fraction form
    681.10/1,020.83 = 420.69/x
  3. Step 3: Cross multiply
    681.10x = 1,020.83 × 420.69
  4. Step 4: Simplify right side
    681.10x = 429,452.97
  5. Step 5: Solve for x
    x = 429,452.97/681.10
  6. Step 6: Final answer
    x = 630.53

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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.