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Finding the Fourth Proportional to 138.93, 209.20 and 100.67

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Solution

The fourth proportional to 138.93, 209.20 and 100.67 is: 151.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.93 : 209.20 = 100.67 : x
  2. Step 2: Convert to fraction form
    138.93/209.20 = 100.67/x
  3. Step 3: Cross multiply
    138.93x = 209.20 × 100.67
  4. Step 4: Simplify right side
    138.93x = 21,060.16
  5. Step 5: Solve for x
    x = 21,060.16/138.93
  6. Step 6: Final answer
    x = 151.59

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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.