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Finding the Fourth Proportional to 85.94, 128.89 and 76.29

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Solution

The fourth proportional to 85.94, 128.89 and 76.29 is: 114.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.94 : 128.89 = 76.29 : x
  2. Step 2: Convert to fraction form
    85.94/128.89 = 76.29/x
  3. Step 3: Cross multiply
    85.94x = 128.89 × 76.29
  4. Step 4: Simplify right side
    85.94x = 9,833.02
  5. Step 5: Solve for x
    x = 9,833.02/85.94
  6. Step 6: Final answer
    x = 114.42

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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.