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Finding the Fourth Proportional to 681.08, 1,021.36 and 485.40

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Solution

The fourth proportional to 681.08, 1,021.36 and 485.40 is: 727.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.08 : 1,021.36 = 485.40 : x
  2. Step 2: Convert to fraction form
    681.08/1,021.36 = 485.40/x
  3. Step 3: Cross multiply
    681.08x = 1,021.36 × 485.40
  4. Step 4: Simplify right side
    681.08x = 495,768.14
  5. Step 5: Solve for x
    x = 495,768.14/681.08
  6. Step 6: Final answer
    x = 727.91

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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.