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Finding the Fourth Proportional to 80.42, 121.12 and 77.04

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Solution

The fourth proportional to 80.42, 121.12 and 77.04 is: 116.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.42 : 121.12 = 77.04 : x
  2. Step 2: Convert to fraction form
    80.42/121.12 = 77.04/x
  3. Step 3: Cross multiply
    80.42x = 121.12 × 77.04
  4. Step 4: Simplify right side
    80.42x = 9,330.89
  5. Step 5: Solve for x
    x = 9,330.89/80.42
  6. Step 6: Final answer
    x = 116.03

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.