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Finding the Fourth Proportional to 88.62, 122.16 and 72.78

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Solution

The fourth proportional to 88.62, 122.16 and 72.78 is: 100.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    88.62 : 122.16 = 72.78 : x
  2. Step 2: Convert to fraction form
    88.62/122.16 = 72.78/x
  3. Step 3: Cross multiply
    88.62x = 122.16 × 72.78
  4. Step 4: Simplify right side
    88.62x = 8,890.80
  5. Step 5: Solve for x
    x = 8,890.80/88.62
  6. Step 6: Final answer
    x = 100.33

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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.