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Finding the Fourth Proportional to 139.95, 211.01 and 138.42

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Solution

The fourth proportional to 139.95, 211.01 and 138.42 is: 208.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.95 : 211.01 = 138.42 : x
  2. Step 2: Convert to fraction form
    139.95/211.01 = 138.42/x
  3. Step 3: Cross multiply
    139.95x = 211.01 × 138.42
  4. Step 4: Simplify right side
    139.95x = 29,207.31
  5. Step 5: Solve for x
    x = 29,207.31/139.95
  6. Step 6: Final answer
    x = 208.70

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.