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Finding the Fourth Proportional to 428.67, 642.15 and 306.54

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Solution

The fourth proportional to 428.67, 642.15 and 306.54 is: 459.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.67 : 642.15 = 306.54 : x
  2. Step 2: Convert to fraction form
    428.67/642.15 = 306.54/x
  3. Step 3: Cross multiply
    428.67x = 642.15 × 306.54
  4. Step 4: Simplify right side
    428.67x = 196,844.66
  5. Step 5: Solve for x
    x = 196,844.66/428.67
  6. Step 6: Final answer
    x = 459.20

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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.