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Finding the Fourth Proportional to 665.71, 998.61 and 521.17

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Solution

The fourth proportional to 665.71, 998.61 and 521.17 is: 781.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.71 : 998.61 = 521.17 : x
  2. Step 2: Convert to fraction form
    665.71/998.61 = 521.17/x
  3. Step 3: Cross multiply
    665.71x = 998.61 × 521.17
  4. Step 4: Simplify right side
    665.71x = 520,445.57
  5. Step 5: Solve for x
    x = 520,445.57/665.71
  6. Step 6: Final answer
    x = 781.79

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.