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Finding the Fourth Proportional to 428.28, 591.02 and 231.78

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Solution

The fourth proportional to 428.28, 591.02 and 231.78 is: 319.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.28 : 591.02 = 231.78 : x
  2. Step 2: Convert to fraction form
    428.28/591.02 = 231.78/x
  3. Step 3: Cross multiply
    428.28x = 591.02 × 231.78
  4. Step 4: Simplify right side
    428.28x = 136,988.54
  5. Step 5: Solve for x
    x = 136,988.54/428.28
  6. Step 6: Final answer
    x = 319.86

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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.