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Finding the Fourth Proportional to 80, 119.89 and 39.42

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Solution

The fourth proportional to 80, 119.89 and 39.42 is: 59.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    80 : 119.89 = 39.42 : x
  2. Step 2: Convert to fraction form
    80/119.89 = 39.42/x
  3. Step 3: Cross multiply
    80x = 119.89 × 39.42
  4. Step 4: Simplify right side
    80x = 4,726.06
  5. Step 5: Solve for x
    x = 4,726.06/80
  6. Step 6: Final answer
    x = 59.08

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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.