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Finding the Fourth Proportional to 231.80, 347.80 and 145.20

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Solution

The fourth proportional to 231.80, 347.80 and 145.20 is: 217.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    231.80 : 347.80 = 145.20 : x
  2. Step 2: Convert to fraction form
    231.80/347.80 = 145.20/x
  3. Step 3: Cross multiply
    231.80x = 347.80 × 145.20
  4. Step 4: Simplify right side
    231.80x = 50,500.56
  5. Step 5: Solve for x
    x = 50,500.56/231.80
  6. Step 6: Final answer
    x = 217.86

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.