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Finding the Fourth Proportional to 318.76, 438.13 and 281.72

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Solution

The fourth proportional to 318.76, 438.13 and 281.72 is: 387.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.76 : 438.13 = 281.72 : x
  2. Step 2: Convert to fraction form
    318.76/438.13 = 281.72/x
  3. Step 3: Cross multiply
    318.76x = 438.13 × 281.72
  4. Step 4: Simplify right side
    318.76x = 123,429.98
  5. Step 5: Solve for x
    x = 123,429.98/318.76
  6. Step 6: Final answer
    x = 387.22

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.