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Finding the Fourth Proportional to 85.90, 129.59 and 82.56

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Solution

The fourth proportional to 85.90, 129.59 and 82.56 is: 124.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.90 : 129.59 = 82.56 : x
  2. Step 2: Convert to fraction form
    85.90/129.59 = 82.56/x
  3. Step 3: Cross multiply
    85.90x = 129.59 × 82.56
  4. Step 4: Simplify right side
    85.90x = 10,698.95
  5. Step 5: Solve for x
    x = 10,698.95/85.90
  6. Step 6: Final answer
    x = 124.55

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.