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Finding the Fourth Proportional to 72.72, 100.42 and 66.87

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Solution

The fourth proportional to 72.72, 100.42 and 66.87 is: 92.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.72 : 100.42 = 66.87 : x
  2. Step 2: Convert to fraction form
    72.72/100.42 = 66.87/x
  3. Step 3: Cross multiply
    72.72x = 100.42 × 66.87
  4. Step 4: Simplify right side
    72.72x = 6,715.09
  5. Step 5: Solve for x
    x = 6,715.09/72.72
  6. Step 6: Final answer
    x = 92.34

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.