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Finding the Fourth Proportional to 86.80, 119.79 and 47.99

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Solution

The fourth proportional to 86.80, 119.79 and 47.99 is: 66.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.80 : 119.79 = 47.99 : x
  2. Step 2: Convert to fraction form
    86.80/119.79 = 47.99/x
  3. Step 3: Cross multiply
    86.80x = 119.79 × 47.99
  4. Step 4: Simplify right side
    86.80x = 5,747.88
  5. Step 5: Solve for x
    x = 5,747.88/86.80
  6. Step 6: Final answer
    x = 66.22

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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.