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Finding the Fourth Proportional to 139.50, 192.60 and 100.80

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Solution

The fourth proportional to 139.50, 192.60 and 100.80 is: 139.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.50 : 192.60 = 100.80 : x
  2. Step 2: Convert to fraction form
    139.50/192.60 = 100.80/x
  3. Step 3: Cross multiply
    139.50x = 192.60 × 100.80
  4. Step 4: Simplify right side
    139.50x = 19,414.08
  5. Step 5: Solve for x
    x = 19,414.08/139.50
  6. Step 6: Final answer
    x = 139.17

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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.