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Finding the Fourth Proportional to 92.90, 139.30 and 38.80

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Solution

The fourth proportional to 92.90, 139.30 and 38.80 is: 58.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    92.90 : 139.30 = 38.80 : x
  2. Step 2: Convert to fraction form
    92.90/139.30 = 38.80/x
  3. Step 3: Cross multiply
    92.90x = 139.30 × 38.80
  4. Step 4: Simplify right side
    92.90x = 5,404.84
  5. Step 5: Solve for x
    x = 5,404.84/92.90
  6. Step 6: Final answer
    x = 58.18

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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.