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Finding the Fourth Proportional to 311.15, 429.30 and 180.20

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Solution

The fourth proportional to 311.15, 429.30 and 180.20 is: 248.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.15 : 429.30 = 180.20 : x
  2. Step 2: Convert to fraction form
    311.15/429.30 = 180.20/x
  3. Step 3: Cross multiply
    311.15x = 429.30 × 180.20
  4. Step 4: Simplify right side
    311.15x = 77,357.71
  5. Step 5: Solve for x
    x = 77,357.71/311.15
  6. Step 6: Final answer
    x = 248.62

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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.