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Finding the Fourth Proportional to 971.82, 1,340.82 and 640.13

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Solution

The fourth proportional to 971.82, 1,340.82 and 640.13 is: 883.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    971.82 : 1,340.82 = 640.13 : x
  2. Step 2: Convert to fraction form
    971.82/1,340.82 = 640.13/x
  3. Step 3: Cross multiply
    971.82x = 1,340.82 × 640.13
  4. Step 4: Simplify right side
    971.82x = 858,292.40
  5. Step 5: Solve for x
    x = 858,292.40/971.82
  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.