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Finding the Fourth Proportional to 105.20, 145.14 and 80.60

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Solution

The fourth proportional to 105.20, 145.14 and 80.60 is: 111.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.20 : 145.14 = 80.60 : x
  2. Step 2: Convert to fraction form
    105.20/145.14 = 80.60/x
  3. Step 3: Cross multiply
    105.20x = 145.14 × 80.60
  4. Step 4: Simplify right side
    105.20x = 11,698.28
  5. Step 5: Solve for x
    x = 11,698.28/105.20
  6. Step 6: Final answer
    x = 111.20

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.