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Finding the Fourth Proportional to 231.78, 347.18 and 145.15

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Solution

The fourth proportional to 231.78, 347.18 and 145.15 is: 217.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    231.78 : 347.18 = 145.15 : x
  2. Step 2: Convert to fraction form
    231.78/347.18 = 145.15/x
  3. Step 3: Cross multiply
    231.78x = 347.18 × 145.15
  4. Step 4: Simplify right side
    231.78x = 50,393.18
  5. Step 5: Solve for x
    x = 50,393.18/231.78
  6. Step 6: Final answer
    x = 217.42

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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.