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Finding the Fourth Proportional to 318.88, 439.64 and 308.80

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Solution

The fourth proportional to 318.88, 439.64 and 308.80 is: 425.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.88 : 439.64 = 308.80 : x
  2. Step 2: Convert to fraction form
    318.88/439.64 = 308.80/x
  3. Step 3: Cross multiply
    318.88x = 439.64 × 308.80
  4. Step 4: Simplify right side
    318.88x = 135,760.83
  5. Step 5: Solve for x
    x = 135,760.83/318.88
  6. Step 6: Final answer
    x = 425.74

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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.