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Finding the Fourth Proportional to 85.87, 118.31 and 79.79

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Solution

The fourth proportional to 85.87, 118.31 and 79.79 is: 109.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.87 : 118.31 = 79.79 : x
  2. Step 2: Convert to fraction form
    85.87/118.31 = 79.79/x
  3. Step 3: Cross multiply
    85.87x = 118.31 × 79.79
  4. Step 4: Simplify right side
    85.87x = 9,440.45
  5. Step 5: Solve for x
    x = 9,440.45/85.87
  6. Step 6: Final answer
    x = 109.94

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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.