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Finding the Fourth Proportional to 869.88, 1,305 and 458.79

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Solution

The fourth proportional to 869.88, 1,305 and 458.79 is: 688.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    869.88 : 1,305 = 458.79 : x
  2. Step 2: Convert to fraction form
    869.88/1,305 = 458.79/x
  3. Step 3: Cross multiply
    869.88x = 1,305 × 458.79
  4. Step 4: Simplify right side
    869.88x = 598,720.95
  5. Step 5: Solve for x
    x = 598,720.95/869.88
  6. Step 6: Final answer
    x = 688.28

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.