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Finding the Fourth Proportional to 85.26, 117.42 and 81.60

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Solution

The fourth proportional to 85.26, 117.42 and 81.60 is: 112.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.26 : 117.42 = 81.60 : x
  2. Step 2: Convert to fraction form
    85.26/117.42 = 81.60/x
  3. Step 3: Cross multiply
    85.26x = 117.42 × 81.60
  4. Step 4: Simplify right side
    85.26x = 9,581.47
  5. Step 5: Solve for x
    x = 9,581.47/85.26
  6. Step 6: Final answer
    x = 112.38

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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.