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Finding the Fourth Proportional to 72.30, 108.30 and 39.81

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Solution

The fourth proportional to 72.30, 108.30 and 39.81 is: 59.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.30 : 108.30 = 39.81 : x
  2. Step 2: Convert to fraction form
    72.30/108.30 = 39.81/x
  3. Step 3: Cross multiply
    72.30x = 108.30 × 39.81
  4. Step 4: Simplify right side
    72.30x = 4,311.42
  5. Step 5: Solve for x
    x = 4,311.42/72.30
  6. Step 6: Final answer
    x = 59.63

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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.