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Finding the Fourth Proportional to 139.95, 209.75 and 79.11

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Solution

The fourth proportional to 139.95, 209.75 and 79.11 is: 118.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.95 : 209.75 = 79.11 : x
  2. Step 2: Convert to fraction form
    139.95/209.75 = 79.11/x
  3. Step 3: Cross multiply
    139.95x = 209.75 × 79.11
  4. Step 4: Simplify right side
    139.95x = 16,593.71
  5. Step 5: Solve for x
    x = 16,593.71/139.95
  6. Step 6: Final answer
    x = 118.57

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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.