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Finding the Fourth Proportional to 138.65, 208.10 and 98.08

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Solution

The fourth proportional to 138.65, 208.10 and 98.08 is: 147.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.65 : 208.10 = 98.08 : x
  2. Step 2: Convert to fraction form
    138.65/208.10 = 98.08/x
  3. Step 3: Cross multiply
    138.65x = 208.10 × 98.08
  4. Step 4: Simplify right side
    138.65x = 20,410.17
  5. Step 5: Solve for x
    x = 20,410.17/138.65
  6. Step 6: Final answer
    x = 147.21

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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.