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Finding the Fourth Proportional to 120.90, 181.43 and 69.51

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Solution

The fourth proportional to 120.90, 181.43 and 69.51 is: 104.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.90 : 181.43 = 69.51 : x
  2. Step 2: Convert to fraction form
    120.90/181.43 = 69.51/x
  3. Step 3: Cross multiply
    120.90x = 181.43 × 69.51
  4. Step 4: Simplify right side
    120.90x = 12,611.20
  5. Step 5: Solve for x
    x = 12,611.20/120.90
  6. Step 6: Final answer
    x = 104.31

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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.