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Finding the Fourth Proportional to 139.70, 192.81 and 103.05

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Solution

The fourth proportional to 139.70, 192.81 and 103.05 is: 142.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.70 : 192.81 = 103.05 : x
  2. Step 2: Convert to fraction form
    139.70/192.81 = 103.05/x
  3. Step 3: Cross multiply
    139.70x = 192.81 × 103.05
  4. Step 4: Simplify right side
    139.70x = 19,869.07
  5. Step 5: Solve for x
    x = 19,869.07/139.70
  6. Step 6: Final answer
    x = 142.23

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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.