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Finding the Fourth Proportional to 318.96, 439.74 and 279.20

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Solution

The fourth proportional to 318.96, 439.74 and 279.20 is: 384.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.96 : 439.74 = 279.20 : x
  2. Step 2: Convert to fraction form
    318.96/439.74 = 279.20/x
  3. Step 3: Cross multiply
    318.96x = 439.74 × 279.20
  4. Step 4: Simplify right side
    318.96x = 122,775.41
  5. Step 5: Solve for x
    x = 122,775.41/318.96
  6. Step 6: Final answer
    x = 384.92

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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.