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Finding the Fourth Proportional to 80.30, 120.72 and 78.26

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Solution

The fourth proportional to 80.30, 120.72 and 78.26 is: 117.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.30 : 120.72 = 78.26 : x
  2. Step 2: Convert to fraction form
    80.30/120.72 = 78.26/x
  3. Step 3: Cross multiply
    80.30x = 120.72 × 78.26
  4. Step 4: Simplify right side
    80.30x = 9,447.55
  5. Step 5: Solve for x
    x = 9,447.55/80.30
  6. Step 6: Final answer
    x = 117.65

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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.