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Finding the Fourth Proportional to 824.10, 1,138.42 and 720.82

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Solution

The fourth proportional to 824.10, 1,138.42 and 720.82 is: 995.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    824.10 : 1,138.42 = 720.82 : x
  2. Step 2: Convert to fraction form
    824.10/1,138.42 = 720.82/x
  3. Step 3: Cross multiply
    824.10x = 1,138.42 × 720.82
  4. Step 4: Simplify right side
    824.10x = 820,595.90
  5. Step 5: Solve for x
    x = 820,595.90/824.10
  6. Step 6: Final answer
    x = 995.75

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.