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Finding the Fourth Proportional to 85.90, 118.51 and 52.70

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Solution

The fourth proportional to 85.90, 118.51 and 52.70 is: 72.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.90 : 118.51 = 52.70 : x
  2. Step 2: Convert to fraction form
    85.90/118.51 = 52.70/x
  3. Step 3: Cross multiply
    85.90x = 118.51 × 52.70
  4. Step 4: Simplify right side
    85.90x = 6,245.48
  5. Step 5: Solve for x
    x = 6,245.48/85.90
  6. Step 6: Final answer
    x = 72.71

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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.