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Finding the Fourth Proportional to 139.34, 191.72 and 115.65

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Solution

The fourth proportional to 139.34, 191.72 and 115.65 is: 159.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.34 : 191.72 = 115.65 : x
  2. Step 2: Convert to fraction form
    139.34/191.72 = 115.65/x
  3. Step 3: Cross multiply
    139.34x = 191.72 × 115.65
  4. Step 4: Simplify right side
    139.34x = 22,172.71
  5. Step 5: Solve for x
    x = 22,172.71/139.34
  6. Step 6: Final answer
    x = 159.12

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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.