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Finding the Fourth Proportional to 79.80, 119.80 and 39.28

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Solution

The fourth proportional to 79.80, 119.80 and 39.28 is: 58.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.80 : 119.80 = 39.28 : x
  2. Step 2: Convert to fraction form
    79.80/119.80 = 39.28/x
  3. Step 3: Cross multiply
    79.80x = 119.80 × 39.28
  4. Step 4: Simplify right side
    79.80x = 4,705.74
  5. Step 5: Solve for x
    x = 4,705.74/79.80
  6. Step 6: Final answer
    x = 58.97

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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.