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Finding the Fourth Proportional to 139.05, 207.90 and 102.60

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Solution

The fourth proportional to 139.05, 207.90 and 102.60 is: 153.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.05 : 207.90 = 102.60 : x
  2. Step 2: Convert to fraction form
    139.05/207.90 = 102.60/x
  3. Step 3: Cross multiply
    139.05x = 207.90 × 102.60
  4. Step 4: Simplify right side
    139.05x = 21,330.54
  5. Step 5: Solve for x
    x = 21,330.54/139.05
  6. Step 6: Final answer
    x = 153.40

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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.