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Finding the Fourth Proportional to 72.70, 108.95 and 65.81

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Solution

The fourth proportional to 72.70, 108.95 and 65.81 is: 98.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.70 : 108.95 = 65.81 : x
  2. Step 2: Convert to fraction form
    72.70/108.95 = 65.81/x
  3. Step 3: Cross multiply
    72.70x = 108.95 × 65.81
  4. Step 4: Simplify right side
    72.70x = 7,169.94
  5. Step 5: Solve for x
    x = 7,169.94/72.70
  6. Step 6: Final answer
    x = 98.63

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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.