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Finding the Fourth Proportional to 85.70, 118.16 and 63.86

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Solution

The fourth proportional to 85.70, 118.16 and 63.86 is: 88.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.70 : 118.16 = 63.86 : x
  2. Step 2: Convert to fraction form
    85.70/118.16 = 63.86/x
  3. Step 3: Cross multiply
    85.70x = 118.16 × 63.86
  4. Step 4: Simplify right side
    85.70x = 7,545.70
  5. Step 5: Solve for x
    x = 7,545.70/85.70
  6. Step 6: Final answer
    x = 88.05

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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.