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Finding the Fourth Proportional to 827.91, 1,141.76 and 640.80

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Solution

The fourth proportional to 827.91, 1,141.76 and 640.80 is: 883.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    827.91 : 1,141.76 = 640.80 : x
  2. Step 2: Convert to fraction form
    827.91/1,141.76 = 640.80/x
  3. Step 3: Cross multiply
    827.91x = 1,141.76 × 640.80
  4. Step 4: Simplify right side
    827.91x = 731,636.60
  5. Step 5: Solve for x
    x = 731,636.60/827.91
  6. Step 6: Final answer
    x = 883.72

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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.