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Finding the Fourth Proportional to 120.90, 181.35 and 75.18

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Solution

The fourth proportional to 120.90, 181.35 and 75.18 is: 112.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.90 : 181.35 = 75.18 : x
  2. Step 2: Convert to fraction form
    120.90/181.35 = 75.18/x
  3. Step 3: Cross multiply
    120.90x = 181.35 × 75.18
  4. Step 4: Simplify right side
    120.90x = 13,633.89
  5. Step 5: Solve for x
    x = 13,633.89/120.90
  6. Step 6: Final answer
    x = 112.77

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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.