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Finding the Fourth Proportional to 139.48, 208.90 and 104.81

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Solution

The fourth proportional to 139.48, 208.90 and 104.81 is: 156.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.48 : 208.90 = 104.81 : x
  2. Step 2: Convert to fraction form
    139.48/208.90 = 104.81/x
  3. Step 3: Cross multiply
    139.48x = 208.90 × 104.81
  4. Step 4: Simplify right side
    139.48x = 21,895.07
  5. Step 5: Solve for x
    x = 21,895.07/139.48
  6. Step 6: Final answer
    x = 156.98

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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.