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Finding the Fourth Proportional to 312.08, 431.16 and 279.44

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Solution

The fourth proportional to 312.08, 431.16 and 279.44 is: 386.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.08 : 431.16 = 279.44 : x
  2. Step 2: Convert to fraction form
    312.08/431.16 = 279.44/x
  3. Step 3: Cross multiply
    312.08x = 431.16 × 279.44
  4. Step 4: Simplify right side
    312.08x = 120,483.35
  5. Step 5: Solve for x
    x = 120,483.35/312.08
  6. Step 6: Final answer
    x = 386.07

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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.