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Finding the Fourth Proportional to 120.90, 166.83 and 71.77

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Solution

The fourth proportional to 120.90, 166.83 and 71.77 is: 99.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.90 : 166.83 = 71.77 : x
  2. Step 2: Convert to fraction form
    120.90/166.83 = 71.77/x
  3. Step 3: Cross multiply
    120.90x = 166.83 × 71.77
  4. Step 4: Simplify right side
    120.90x = 11,973.39
  5. Step 5: Solve for x
    x = 11,973.39/120.90
  6. Step 6: Final answer
    x = 99.04

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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.