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Finding the Fourth Proportional to 80.58, 110.40 and 78.60

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Solution

The fourth proportional to 80.58, 110.40 and 78.60 is: 107.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.58 : 110.40 = 78.60 : x
  2. Step 2: Convert to fraction form
    80.58/110.40 = 78.60/x
  3. Step 3: Cross multiply
    80.58x = 110.40 × 78.60
  4. Step 4: Simplify right side
    80.58x = 8,677.44
  5. Step 5: Solve for x
    x = 8,677.44/80.58
  6. Step 6: Final answer
    x = 107.69

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.