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Finding the Fourth Proportional to 139.45, 208.94 and 98.81

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Solution

The fourth proportional to 139.45, 208.94 and 98.81 is: 148.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.45 : 208.94 = 98.81 : x
  2. Step 2: Convert to fraction form
    139.45/208.94 = 98.81/x
  3. Step 3: Cross multiply
    139.45x = 208.94 × 98.81
  4. Step 4: Simplify right side
    139.45x = 20,643.82
  5. Step 5: Solve for x
    x = 20,643.82/139.45
  6. Step 6: Final answer
    x = 148.04

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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.