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Finding the Fourth Proportional to 80.71, 121.06 and 65.42

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Solution

The fourth proportional to 80.71, 121.06 and 65.42 is: 98.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.71 : 121.06 = 65.42 : x
  2. Step 2: Convert to fraction form
    80.71/121.06 = 65.42/x
  3. Step 3: Cross multiply
    80.71x = 121.06 × 65.42
  4. Step 4: Simplify right side
    80.71x = 7,919.75
  5. Step 5: Solve for x
    x = 7,919.75/80.71
  6. Step 6: Final answer
    x = 98.13

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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.