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Finding the Fourth Proportional to 92.80, 139.16 and 54.30

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Solution

The fourth proportional to 92.80, 139.16 and 54.30 is: 81.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    92.80 : 139.16 = 54.30 : x
  2. Step 2: Convert to fraction form
    92.80/139.16 = 54.30/x
  3. Step 3: Cross multiply
    92.80x = 139.16 × 54.30
  4. Step 4: Simplify right side
    92.80x = 7,555.83
  5. Step 5: Solve for x
    x = 7,555.83/92.80
  6. Step 6: Final answer
    x = 81.42

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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.