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Finding the Fourth Proportional to 311.40, 429.70 and 171.50

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Solution

The fourth proportional to 311.40, 429.70 and 171.50 is: 236.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.40 : 429.70 = 171.50 : x
  2. Step 2: Convert to fraction form
    311.40/429.70 = 171.50/x
  3. Step 3: Cross multiply
    311.40x = 429.70 × 171.50
  4. Step 4: Simplify right side
    311.40x = 73,693.55
  5. Step 5: Solve for x
    x = 73,693.55/311.40
  6. Step 6: Final answer
    x = 236.65

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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.