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Finding the Fourth Proportional to 312.28, 431.30 and 275.56

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Solution

The fourth proportional to 312.28, 431.30 and 275.56 is: 380.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.28 : 431.30 = 275.56 : x
  2. Step 2: Convert to fraction form
    312.28/431.30 = 275.56/x
  3. Step 3: Cross multiply
    312.28x = 431.30 × 275.56
  4. Step 4: Simplify right side
    312.28x = 118,849.03
  5. Step 5: Solve for x
    x = 118,849.03/312.28
  6. Step 6: Final answer
    x = 380.58

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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.