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Finding the Fourth Proportional to 717.90, 990.56 and 496.78

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Solution

The fourth proportional to 717.90, 990.56 and 496.78 is: 685.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    717.90 : 990.56 = 496.78 : x
  2. Step 2: Convert to fraction form
    717.90/990.56 = 496.78/x
  3. Step 3: Cross multiply
    717.90x = 990.56 × 496.78
  4. Step 4: Simplify right side
    717.90x = 492,090.40
  5. Step 5: Solve for x
    x = 492,090.40/717.90
  6. Step 6: Final answer
    x = 685.46

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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.