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Finding the Fourth Proportional to 78.20, 107.96 and 58.80

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Solution

The fourth proportional to 78.20, 107.96 and 58.80 is: 81.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.20 : 107.96 = 58.80 : x
  2. Step 2: Convert to fraction form
    78.20/107.96 = 58.80/x
  3. Step 3: Cross multiply
    78.20x = 107.96 × 58.80
  4. Step 4: Simplify right side
    78.20x = 6,348.05
  5. Step 5: Solve for x
    x = 6,348.05/78.20
  6. Step 6: Final answer
    x = 81.18

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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.