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Finding the Fourth Proportional to 88.40, 122.04 and 78.80

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Solution

The fourth proportional to 88.40, 122.04 and 78.80 is: 108.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    88.40 : 122.04 = 78.80 : x
  2. Step 2: Convert to fraction form
    88.40/122.04 = 78.80/x
  3. Step 3: Cross multiply
    88.40x = 122.04 × 78.80
  4. Step 4: Simplify right side
    88.40x = 9,616.75
  5. Step 5: Solve for x
    x = 9,616.75/88.40
  6. Step 6: Final answer
    x = 108.79

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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.