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Finding the Fourth Proportional to 312.39, 431.04 and 177.78

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Solution

The fourth proportional to 312.39, 431.04 and 177.78 is: 245.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.39 : 431.04 = 177.78 : x
  2. Step 2: Convert to fraction form
    312.39/431.04 = 177.78/x
  3. Step 3: Cross multiply
    312.39x = 431.04 × 177.78
  4. Step 4: Simplify right side
    312.39x = 76,628.67
  5. Step 5: Solve for x
    x = 76,628.67/312.39
  6. Step 6: Final answer
    x = 245.30

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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.