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Finding the Fourth Proportional to 72.18, 108.34 and 45.15

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Solution

The fourth proportional to 72.18, 108.34 and 45.15 is: 67.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.18 : 108.34 = 45.15 : x
  2. Step 2: Convert to fraction form
    72.18/108.34 = 45.15/x
  3. Step 3: Cross multiply
    72.18x = 108.34 × 45.15
  4. Step 4: Simplify right side
    72.18x = 4,891.03
  5. Step 5: Solve for x
    x = 4,891.03/72.18
  6. Step 6: Final answer
    x = 67.76

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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.