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Finding the Fourth Proportional to 80.74, 120.43 and 78.08

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Solution

The fourth proportional to 80.74, 120.43 and 78.08 is: 116.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.74 : 120.43 = 78.08 : x
  2. Step 2: Convert to fraction form
    80.74/120.43 = 78.08/x
  3. Step 3: Cross multiply
    80.74x = 120.43 × 78.08
  4. Step 4: Simplify right side
    80.74x = 9,402.57
  5. Step 5: Solve for x
    x = 9,402.57/80.74
  6. Step 6: Final answer
    x = 116.46

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.