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Finding the Fourth Proportional to 717.61, 990.30 and 402.86

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Solution

The fourth proportional to 717.61, 990.30 and 402.86 is: 555.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    717.61 : 990.30 = 402.86 : x
  2. Step 2: Convert to fraction form
    717.61/990.30 = 402.86/x
  3. Step 3: Cross multiply
    717.61x = 990.30 × 402.86
  4. Step 4: Simplify right side
    717.61x = 398,953.72
  5. Step 5: Solve for x
    x = 398,953.72/717.61
  6. Step 6: Final answer
    x = 555.95

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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.