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Finding the Fourth Proportional to 717.68, 990.28 and 402.88

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Solution

The fourth proportional to 717.68, 990.28 and 402.88 is: 555.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    717.68 : 990.28 = 402.88 : x
  2. Step 2: Convert to fraction form
    717.68/990.28 = 402.88/x
  3. Step 3: Cross multiply
    717.68x = 990.28 × 402.88
  4. Step 4: Simplify right side
    717.68x = 398,964.01
  5. Step 5: Solve for x
    x = 398,964.01/717.68
  6. Step 6: Final answer
    x = 555.91

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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.