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Finding the Fourth Proportional to 806.42, 1,112.18 and 640.38

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Solution

The fourth proportional to 806.42, 1,112.18 and 640.38 is: 883.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    806.42 : 1,112.18 = 640.38 : x
  2. Step 2: Convert to fraction form
    806.42/1,112.18 = 640.38/x
  3. Step 3: Cross multiply
    806.42x = 1,112.18 × 640.38
  4. Step 4: Simplify right side
    806.42x = 712,217.83
  5. Step 5: Solve for x
    x = 712,217.83/806.42
  6. Step 6: Final answer
    x = 883.18

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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.