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Finding the Fourth Proportional to 85, 127.51 and 65.85

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Solution

The fourth proportional to 85, 127.51 and 65.85 is: 98.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    85 : 127.51 = 65.85 : x
  2. Step 2: Convert to fraction form
    85/127.51 = 65.85/x
  3. Step 3: Cross multiply
    85x = 127.51 × 65.85
  4. Step 4: Simplify right side
    85x = 8,396.53
  5. Step 5: Solve for x
    x = 8,396.53/85
  6. Step 6: Final answer
    x = 98.78

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.