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Finding the Fourth Proportional to 139.15, 208.61 and 52.45

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Solution

The fourth proportional to 139.15, 208.61 and 52.45 is: 78.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.15 : 208.61 = 52.45 : x
  2. Step 2: Convert to fraction form
    139.15/208.61 = 52.45/x
  3. Step 3: Cross multiply
    139.15x = 208.61 × 52.45
  4. Step 4: Simplify right side
    139.15x = 10,941.01
  5. Step 5: Solve for x
    x = 10,941.01/139.15
  6. Step 6: Final answer
    x = 78.63

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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.