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Finding the Fourth Proportional to 310.85, 428.52 and 217.30

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Solution

The fourth proportional to 310.85, 428.52 and 217.30 is: 299.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    310.85 : 428.52 = 217.30 : x
  2. Step 2: Convert to fraction form
    310.85/428.52 = 217.30/x
  3. Step 3: Cross multiply
    310.85x = 428.52 × 217.30
  4. Step 4: Simplify right side
    310.85x = 93,116.51
  5. Step 5: Solve for x
    x = 93,116.51/310.85
  6. Step 6: Final answer
    x = 299.56

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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.