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Finding the Fourth Proportional to 85.60, 118.05 and 83.20

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Solution

The fourth proportional to 85.60, 118.05 and 83.20 is: 114.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.60 : 118.05 = 83.20 : x
  2. Step 2: Convert to fraction form
    85.60/118.05 = 83.20/x
  3. Step 3: Cross multiply
    85.60x = 118.05 × 83.20
  4. Step 4: Simplify right side
    85.60x = 9,821.76
  5. Step 5: Solve for x
    x = 9,821.76/85.60
  6. Step 6: Final answer
    x = 114.74

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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.