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Finding the Fourth Proportional to 85.38, 117.86 and 57.89

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Solution

The fourth proportional to 85.38, 117.86 and 57.89 is: 79.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.38 : 117.86 = 57.89 : x
  2. Step 2: Convert to fraction form
    85.38/117.86 = 57.89/x
  3. Step 3: Cross multiply
    85.38x = 117.86 × 57.89
  4. Step 4: Simplify right side
    85.38x = 6,822.59
  5. Step 5: Solve for x
    x = 6,822.59/85.38
  6. Step 6: Final answer
    x = 79.91

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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.