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Finding the Fourth Proportional to 85.31, 117.61 and 68.91

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Solution

The fourth proportional to 85.31, 117.61 and 68.91 is: 95.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.31 : 117.61 = 68.91 : x
  2. Step 2: Convert to fraction form
    85.31/117.61 = 68.91/x
  3. Step 3: Cross multiply
    85.31x = 117.61 × 68.91
  4. Step 4: Simplify right side
    85.31x = 8,104.51
  5. Step 5: Solve for x
    x = 8,104.51/85.31
  6. Step 6: Final answer
    x = 95.00

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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.