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Finding the Fourth Proportional to 428.13, 641.79 and 306.36

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Solution

The fourth proportional to 428.13, 641.79 and 306.36 is: 459.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.13 : 641.79 = 306.36 : x
  2. Step 2: Convert to fraction form
    428.13/641.79 = 306.36/x
  3. Step 3: Cross multiply
    428.13x = 641.79 × 306.36
  4. Step 4: Simplify right side
    428.13x = 196,618.78
  5. Step 5: Solve for x
    x = 196,618.78/428.13
  6. Step 6: Final answer
    x = 459.25

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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.