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Finding the Fourth Proportional to 85.60, 118.14 and 83.80

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Solution

The fourth proportional to 85.60, 118.14 and 83.80 is: 115.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.60 : 118.14 = 83.80 : x
  2. Step 2: Convert to fraction form
    85.60/118.14 = 83.80/x
  3. Step 3: Cross multiply
    85.60x = 118.14 × 83.80
  4. Step 4: Simplify right side
    85.60x = 9,900.13
  5. Step 5: Solve for x
    x = 9,900.13/85.60
  6. Step 6: Final answer
    x = 115.66

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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.