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Finding the Fourth Proportional to 139.83, 209.73 and 71.43

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Solution

The fourth proportional to 139.83, 209.73 and 71.43 is: 107.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.83 : 209.73 = 71.43 : x
  2. Step 2: Convert to fraction form
    139.83/209.73 = 71.43/x
  3. Step 3: Cross multiply
    139.83x = 209.73 × 71.43
  4. Step 4: Simplify right side
    139.83x = 14,981.01
  5. Step 5: Solve for x
    x = 14,981.01/139.83
  6. Step 6: Final answer
    x = 107.14

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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.