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Finding the Fourth Proportional to 139.42, 209.15 and 43.23

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Solution

The fourth proportional to 139.42, 209.15 and 43.23 is: 64.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.42 : 209.15 = 43.23 : x
  2. Step 2: Convert to fraction form
    139.42/209.15 = 43.23/x
  3. Step 3: Cross multiply
    139.42x = 209.15 × 43.23
  4. Step 4: Simplify right side
    139.42x = 9,042.28
  5. Step 5: Solve for x
    x = 9,042.28/139.42
  6. Step 6: Final answer
    x = 64.86

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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.