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Finding the Fourth Proportional to 428.31, 641.88 and 154.13

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Solution

The fourth proportional to 428.31, 641.88 and 154.13 is: 230.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.31 : 641.88 = 154.13 : x
  2. Step 2: Convert to fraction form
    428.31/641.88 = 154.13/x
  3. Step 3: Cross multiply
    428.31x = 641.88 × 154.13
  4. Step 4: Simplify right side
    428.31x = 98,929.76
  5. Step 5: Solve for x
    x = 98,929.76/428.31
  6. Step 6: Final answer
    x = 230.98

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.