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Finding the Fourth Proportional to 80.96, 121.56 and 66.36

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Solution

The fourth proportional to 80.96, 121.56 and 66.36 is: 99.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.96 : 121.56 = 66.36 : x
  2. Step 2: Convert to fraction form
    80.96/121.56 = 66.36/x
  3. Step 3: Cross multiply
    80.96x = 121.56 × 66.36
  4. Step 4: Simplify right side
    80.96x = 8,066.72
  5. Step 5: Solve for x
    x = 8,066.72/80.96
  6. Step 6: Final answer
    x = 99.64

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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.