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Finding the Fourth Proportional to 72.99, 109.52 and 38.78

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Solution

The fourth proportional to 72.99, 109.52 and 38.78 is: 58.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.99 : 109.52 = 38.78 : x
  2. Step 2: Convert to fraction form
    72.99/109.52 = 38.78/x
  3. Step 3: Cross multiply
    72.99x = 109.52 × 38.78
  4. Step 4: Simplify right side
    72.99x = 4,246.44
  5. Step 5: Solve for x
    x = 4,246.44/72.99
  6. Step 6: Final answer
    x = 58.18

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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.