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Finding the Fourth Proportional to 88.90, 122.40 and 82.78

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Solution

The fourth proportional to 88.90, 122.40 and 82.78 is: 113.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    88.90 : 122.40 = 82.78 : x
  2. Step 2: Convert to fraction form
    88.90/122.40 = 82.78/x
  3. Step 3: Cross multiply
    88.90x = 122.40 × 82.78
  4. Step 4: Simplify right side
    88.90x = 10,132.27
  5. Step 5: Solve for x
    x = 10,132.27/88.90
  6. Step 6: Final answer
    x = 113.97

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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.