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Finding the Fourth Proportional to 717.80, 990.42 and 496.40

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Solution

The fourth proportional to 717.80, 990.42 and 496.40 is: 684.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    717.80 : 990.42 = 496.40 : x
  2. Step 2: Convert to fraction form
    717.80/990.42 = 496.40/x
  3. Step 3: Cross multiply
    717.80x = 990.42 × 496.40
  4. Step 4: Simplify right side
    717.80x = 491,644.49
  5. Step 5: Solve for x
    x = 491,644.49/717.80
  6. Step 6: Final answer
    x = 684.93

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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.