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Finding the Fourth Proportional to 85.72, 128.58 and 27.94

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Solution

The fourth proportional to 85.72, 128.58 and 27.94 is: 41.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.72 : 128.58 = 27.94 : x
  2. Step 2: Convert to fraction form
    85.72/128.58 = 27.94/x
  3. Step 3: Cross multiply
    85.72x = 128.58 × 27.94
  4. Step 4: Simplify right side
    85.72x = 3,592.53
  5. Step 5: Solve for x
    x = 3,592.53/85.72
  6. Step 6: Final answer
    x = 41.91

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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.