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Finding the Fourth Proportional to 139.20, 191.95 and 90.10

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Solution

The fourth proportional to 139.20, 191.95 and 90.10 is: 124.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.20 : 191.95 = 90.10 : x
  2. Step 2: Convert to fraction form
    139.20/191.95 = 90.10/x
  3. Step 3: Cross multiply
    139.20x = 191.95 × 90.10
  4. Step 4: Simplify right side
    139.20x = 17,294.70
  5. Step 5: Solve for x
    x = 17,294.70/139.20
  6. Step 6: Final answer
    x = 124.24

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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.