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Finding the Fourth Proportional to 679.99, 938.78 and 447.79

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Solution

The fourth proportional to 679.99, 938.78 and 447.79 is: 618.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.99 : 938.78 = 447.79 : x
  2. Step 2: Convert to fraction form
    679.99/938.78 = 447.79/x
  3. Step 3: Cross multiply
    679.99x = 938.78 × 447.79
  4. Step 4: Simplify right side
    679.99x = 420,374.06
  5. Step 5: Solve for x
    x = 420,374.06/679.99
  6. Step 6: Final answer
    x = 618.21

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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.