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Finding the Fourth Proportional to 85.82, 118.55 and 78.53

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Solution

The fourth proportional to 85.82, 118.55 and 78.53 is: 108.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.82 : 118.55 = 78.53 : x
  2. Step 2: Convert to fraction form
    85.82/118.55 = 78.53/x
  3. Step 3: Cross multiply
    85.82x = 118.55 × 78.53
  4. Step 4: Simplify right side
    85.82x = 9,309.73
  5. Step 5: Solve for x
    x = 9,309.73/85.82
  6. Step 6: Final answer
    x = 108.48

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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.