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Finding the Fourth Proportional to 399, 550.65 and 243.78

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Solution

The fourth proportional to 399, 550.65 and 243.78 is: 336.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    399 : 550.65 = 243.78 : x
  2. Step 2: Convert to fraction form
    399/550.65 = 243.78/x
  3. Step 3: Cross multiply
    399x = 550.65 × 243.78
  4. Step 4: Simplify right side
    399x = 134,237.46
  5. Step 5: Solve for x
    x = 134,237.46/399
  6. Step 6: Final answer
    x = 336.43

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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.