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Finding the Fourth Proportional to 717.85, 990.69 and 403.18

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Solution

The fourth proportional to 717.85, 990.69 and 403.18 is: 556.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    717.85 : 990.69 = 403.18 : x
  2. Step 2: Convert to fraction form
    717.85/990.69 = 403.18/x
  3. Step 3: Cross multiply
    717.85x = 990.69 × 403.18
  4. Step 4: Simplify right side
    717.85x = 399,426.39
  5. Step 5: Solve for x
    x = 399,426.39/717.85
  6. Step 6: Final answer
    x = 556.42

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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.