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Finding the Fourth Proportional to 130.25, 179.75 and 81.20

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Solution

The fourth proportional to 130.25, 179.75 and 81.20 is: 112.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    130.25 : 179.75 = 81.20 : x
  2. Step 2: Convert to fraction form
    130.25/179.75 = 81.20/x
  3. Step 3: Cross multiply
    130.25x = 179.75 × 81.20
  4. Step 4: Simplify right side
    130.25x = 14,595.70
  5. Step 5: Solve for x
    x = 14,595.70/130.25
  6. Step 6: Final answer
    x = 112.06

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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.