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Finding the Fourth Proportional to 428.33, 641.78 and 312.62

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Solution

The fourth proportional to 428.33, 641.78 and 312.62 is: 468.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.33 : 641.78 = 312.62 : x
  2. Step 2: Convert to fraction form
    428.33/641.78 = 312.62/x
  3. Step 3: Cross multiply
    428.33x = 641.78 × 312.62
  4. Step 4: Simplify right side
    428.33x = 200,629.66
  5. Step 5: Solve for x
    x = 200,629.66/428.33
  6. Step 6: Final answer
    x = 468.40

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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.