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Finding the Fourth Proportional to 80.78, 120.95 and 53.29

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Solution

The fourth proportional to 80.78, 120.95 and 53.29 is: 79.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.78 : 120.95 = 53.29 : x
  2. Step 2: Convert to fraction form
    80.78/120.95 = 53.29/x
  3. Step 3: Cross multiply
    80.78x = 120.95 × 53.29
  4. Step 4: Simplify right side
    80.78x = 6,445.43
  5. Step 5: Solve for x
    x = 6,445.43/80.78
  6. Step 6: Final answer
    x = 79.79

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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.