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Finding the Fourth Proportional to 85.42, 117.82 and 69.89

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Solution

The fourth proportional to 85.42, 117.82 and 69.89 is: 96.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.42 : 117.82 = 69.89 : x
  2. Step 2: Convert to fraction form
    85.42/117.82 = 69.89/x
  3. Step 3: Cross multiply
    85.42x = 117.82 × 69.89
  4. Step 4: Simplify right side
    85.42x = 8,234.44
  5. Step 5: Solve for x
    x = 8,234.44/85.42
  6. Step 6: Final answer
    x = 96.40

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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.