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Finding the Fourth Proportional to 310.79, 428.90 and 170.90

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Solution

The fourth proportional to 310.79, 428.90 and 170.90 is: 235.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    310.79 : 428.90 = 170.90 : x
  2. Step 2: Convert to fraction form
    310.79/428.90 = 170.90/x
  3. Step 3: Cross multiply
    310.79x = 428.90 × 170.90
  4. Step 4: Simplify right side
    310.79x = 73,299.01
  5. Step 5: Solve for x
    x = 73,299.01/310.79
  6. Step 6: Final answer
    x = 235.85

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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.