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Finding the Fourth Proportional to 717.78, 990.72 and 469.72

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Solution

The fourth proportional to 717.78, 990.72 and 469.72 is: 648.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    717.78 : 990.72 = 469.72 : x
  2. Step 2: Convert to fraction form
    717.78/990.72 = 469.72/x
  3. Step 3: Cross multiply
    717.78x = 990.72 × 469.72
  4. Step 4: Simplify right side
    717.78x = 465,361.00
  5. Step 5: Solve for x
    x = 465,361.00/717.78
  6. Step 6: Final answer
    x = 648.33

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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.