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Finding the Fourth Proportional to 86.03, 129.05 and 31.19

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Solution

The fourth proportional to 86.03, 129.05 and 31.19 is: 46.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.03 : 129.05 = 31.19 : x
  2. Step 2: Convert to fraction form
    86.03/129.05 = 31.19/x
  3. Step 3: Cross multiply
    86.03x = 129.05 × 31.19
  4. Step 4: Simplify right side
    86.03x = 4,024.47
  5. Step 5: Solve for x
    x = 4,024.47/86.03
  6. Step 6: Final answer
    x = 46.78

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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.