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Finding the Fourth Proportional to 663.29, 994.78 and 389.91

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Solution

The fourth proportional to 663.29, 994.78 and 389.91 is: 584.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    663.29 : 994.78 = 389.91 : x
  2. Step 2: Convert to fraction form
    663.29/994.78 = 389.91/x
  3. Step 3: Cross multiply
    663.29x = 994.78 × 389.91
  4. Step 4: Simplify right side
    663.29x = 387,878.89
  5. Step 5: Solve for x
    x = 387,878.89/663.29
  6. Step 6: Final answer
    x = 584.78

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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.