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Finding the Fourth Proportional to 665.86, 997.82 and 521.40

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Solution

The fourth proportional to 665.86, 997.82 and 521.40 is: 781.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.86 : 997.82 = 521.40 : x
  2. Step 2: Convert to fraction form
    665.86/997.82 = 521.40/x
  3. Step 3: Cross multiply
    665.86x = 997.82 × 521.40
  4. Step 4: Simplify right side
    665.86x = 520,263.35
  5. Step 5: Solve for x
    x = 520,263.35/665.86
  6. Step 6: Final answer
    x = 781.34

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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.