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Finding the Fourth Proportional to 824.38, 1,138.56 and 640.10

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Solution

The fourth proportional to 824.38, 1,138.56 and 640.10 is: 884.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    824.38 : 1,138.56 = 640.10 : x
  2. Step 2: Convert to fraction form
    824.38/1,138.56 = 640.10/x
  3. Step 3: Cross multiply
    824.38x = 1,138.56 × 640.10
  4. Step 4: Simplify right side
    824.38x = 728,792.26
  5. Step 5: Solve for x
    x = 728,792.26/824.38
  6. Step 6: Final answer
    x = 884.05

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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.