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Finding the Fourth Proportional to 139.68, 208.86 and 105.48

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Solution

The fourth proportional to 139.68, 208.86 and 105.48 is: 157.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.68 : 208.86 = 105.48 : x
  2. Step 2: Convert to fraction form
    139.68/208.86 = 105.48/x
  3. Step 3: Cross multiply
    139.68x = 208.86 × 105.48
  4. Step 4: Simplify right side
    139.68x = 22,030.55
  5. Step 5: Solve for x
    x = 22,030.55/139.68
  6. Step 6: Final answer
    x = 157.72

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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.