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Finding the Fourth Proportional to 120.15, 165.75 and 80.88

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Solution

The fourth proportional to 120.15, 165.75 and 80.88 is: 111.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.15 : 165.75 = 80.88 : x
  2. Step 2: Convert to fraction form
    120.15/165.75 = 80.88/x
  3. Step 3: Cross multiply
    120.15x = 165.75 × 80.88
  4. Step 4: Simplify right side
    120.15x = 13,405.86
  5. Step 5: Solve for x
    x = 13,405.86/120.15
  6. Step 6: Final answer
    x = 111.58

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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.