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Finding the Fourth Proportional to 814.68, 1,125.22 and 639.80

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Solution

The fourth proportional to 814.68, 1,125.22 and 639.80 is: 883.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    814.68 : 1,125.22 = 639.80 : x
  2. Step 2: Convert to fraction form
    814.68/1,125.22 = 639.80/x
  3. Step 3: Cross multiply
    814.68x = 1,125.22 × 639.80
  4. Step 4: Simplify right side
    814.68x = 719,915.76
  5. Step 5: Solve for x
    x = 719,915.76/814.68
  6. Step 6: Final answer
    x = 883.68

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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.