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Finding the Fourth Proportional to 80.58, 120.24 and 70.86

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Solution

The fourth proportional to 80.58, 120.24 and 70.86 is: 105.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.58 : 120.24 = 70.86 : x
  2. Step 2: Convert to fraction form
    80.58/120.24 = 70.86/x
  3. Step 3: Cross multiply
    80.58x = 120.24 × 70.86
  4. Step 4: Simplify right side
    80.58x = 8,520.21
  5. Step 5: Solve for x
    x = 8,520.21/80.58
  6. Step 6: Final answer
    x = 105.74

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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.