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Finding the Fourth Proportional to 312.50, 431.16 and 212.78

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Solution

The fourth proportional to 312.50, 431.16 and 212.78 is: 293.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.50 : 431.16 = 212.78 : x
  2. Step 2: Convert to fraction form
    312.50/431.16 = 212.78/x
  3. Step 3: Cross multiply
    312.50x = 431.16 × 212.78
  4. Step 4: Simplify right side
    312.50x = 91,742.22
  5. Step 5: Solve for x
    x = 91,742.22/312.50
  6. Step 6: Final answer
    x = 293.58

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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.