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Finding the Fourth Proportional to 863.40, 1,292.40 and 620.40

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Solution

The fourth proportional to 863.40, 1,292.40 and 620.40 is: 928.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    863.40 : 1,292.40 = 620.40 : x
  2. Step 2: Convert to fraction form
    863.40/1,292.40 = 620.40/x
  3. Step 3: Cross multiply
    863.40x = 1,292.40 × 620.40
  4. Step 4: Simplify right side
    863.40x = 801,804.96
  5. Step 5: Solve for x
    x = 801,804.96/863.40
  6. Step 6: Final answer
    x = 928.66

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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.