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Finding the Fourth Proportional to 310.81, 428.88 and 217.66

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Solution

The fourth proportional to 310.81, 428.88 and 217.66 is: 300.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    310.81 : 428.88 = 217.66 : x
  2. Step 2: Convert to fraction form
    310.81/428.88 = 217.66/x
  3. Step 3: Cross multiply
    310.81x = 428.88 × 217.66
  4. Step 4: Simplify right side
    310.81x = 93,350.02
  5. Step 5: Solve for x
    x = 93,350.02/310.81
  6. Step 6: Final answer
    x = 300.34

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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.