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Finding the Fourth Proportional to 428.09, 641.55 and 306.05

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Solution

The fourth proportional to 428.09, 641.55 and 306.05 is: 458.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.09 : 641.55 = 306.05 : x
  2. Step 2: Convert to fraction form
    428.09/641.55 = 306.05/x
  3. Step 3: Cross multiply
    428.09x = 641.55 × 306.05
  4. Step 4: Simplify right side
    428.09x = 196,344.32
  5. Step 5: Solve for x
    x = 196,344.32/428.09
  6. Step 6: Final answer
    x = 458.66

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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.