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Finding the Fourth Proportional to 139.37, 209.10 and 74.42

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Solution

The fourth proportional to 139.37, 209.10 and 74.42 is: 111.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.37 : 209.10 = 74.42 : x
  2. Step 2: Convert to fraction form
    139.37/209.10 = 74.42/x
  3. Step 3: Cross multiply
    139.37x = 209.10 × 74.42
  4. Step 4: Simplify right side
    139.37x = 15,561.24
  5. Step 5: Solve for x
    x = 15,561.24/139.37
  6. Step 6: Final answer
    x = 111.66

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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.