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Finding the Fourth Proportional to 231.30, 318.84 and 189.78

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Solution

The fourth proportional to 231.30, 318.84 and 189.78 is: 261.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    231.30 : 318.84 = 189.78 : x
  2. Step 2: Convert to fraction form
    231.30/318.84 = 189.78/x
  3. Step 3: Cross multiply
    231.30x = 318.84 × 189.78
  4. Step 4: Simplify right side
    231.30x = 60,509.46
  5. Step 5: Solve for x
    x = 60,509.46/231.30
  6. Step 6: Final answer
    x = 261.61

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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.