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Finding the Fourth Proportional to 318.48, 439.20 and 208.05

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Solution

The fourth proportional to 318.48, 439.20 and 208.05 is: 286.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.48 : 439.20 = 208.05 : x
  2. Step 2: Convert to fraction form
    318.48/439.20 = 208.05/x
  3. Step 3: Cross multiply
    318.48x = 439.20 × 208.05
  4. Step 4: Simplify right side
    318.48x = 91,375.56
  5. Step 5: Solve for x
    x = 91,375.56/318.48
  6. Step 6: Final answer
    x = 286.91

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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.