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Finding the Fourth Proportional to 76.71, 115.05 and 31.08

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Solution

The fourth proportional to 76.71, 115.05 and 31.08 is: 46.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.71 : 115.05 = 31.08 : x
  2. Step 2: Convert to fraction form
    76.71/115.05 = 31.08/x
  3. Step 3: Cross multiply
    76.71x = 115.05 × 31.08
  4. Step 4: Simplify right side
    76.71x = 3,575.75
  5. Step 5: Solve for x
    x = 3,575.75/76.71
  6. Step 6: Final answer
    x = 46.61

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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.