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Finding the Fourth Proportional to 310.47, 428.12 and 217.11

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Solution

The fourth proportional to 310.47, 428.12 and 217.11 is: 299.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    310.47 : 428.12 = 217.11 : x
  2. Step 2: Convert to fraction form
    310.47/428.12 = 217.11/x
  3. Step 3: Cross multiply
    310.47x = 428.12 × 217.11
  4. Step 4: Simplify right side
    310.47x = 92,950.47
  5. Step 5: Solve for x
    x = 92,950.47/310.47
  6. Step 6: Final answer
    x = 299.39

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.