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Finding the Fourth Proportional to 139.10, 208.80 and 113.58

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Solution

The fourth proportional to 139.10, 208.80 and 113.58 is: 170.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.10 : 208.80 = 113.58 : x
  2. Step 2: Convert to fraction form
    139.10/208.80 = 113.58/x
  3. Step 3: Cross multiply
    139.10x = 208.80 × 113.58
  4. Step 4: Simplify right side
    139.10x = 23,715.50
  5. Step 5: Solve for x
    x = 23,715.50/139.10
  6. Step 6: Final answer
    x = 170.50

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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.