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Finding the Fourth Proportional to 120.18, 180.40 and 66.12

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Solution

The fourth proportional to 120.18, 180.40 and 66.12 is: 99.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.18 : 180.40 = 66.12 : x
  2. Step 2: Convert to fraction form
    120.18/180.40 = 66.12/x
  3. Step 3: Cross multiply
    120.18x = 180.40 × 66.12
  4. Step 4: Simplify right side
    120.18x = 11,928.05
  5. Step 5: Solve for x
    x = 11,928.05/120.18
  6. Step 6: Final answer
    x = 99.25

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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.