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Finding the Fourth Proportional to 679.92, 1,020.60 and 488.40

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Solution

The fourth proportional to 679.92, 1,020.60 and 488.40 is: 733.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.92 : 1,020.60 = 488.40 : x
  2. Step 2: Convert to fraction form
    679.92/1,020.60 = 488.40/x
  3. Step 3: Cross multiply
    679.92x = 1,020.60 × 488.40
  4. Step 4: Simplify right side
    679.92x = 498,461.04
  5. Step 5: Solve for x
    x = 498,461.04/679.92
  6. Step 6: Final answer
    x = 733.12

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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.