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Finding the Fourth Proportional to 85.71, 117.96 and 77.96

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Solution

The fourth proportional to 85.71, 117.96 and 77.96 is: 107.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.71 : 117.96 = 77.96 : x
  2. Step 2: Convert to fraction form
    85.71/117.96 = 77.96/x
  3. Step 3: Cross multiply
    85.71x = 117.96 × 77.96
  4. Step 4: Simplify right side
    85.71x = 9,195.57
  5. Step 5: Solve for x
    x = 9,195.57/85.71
  6. Step 6: Final answer
    x = 107.29

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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.