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Finding the Fourth Proportional to 97.81, 135.14 and 85.51

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Solution

The fourth proportional to 97.81, 135.14 and 85.51 is: 118.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    97.81 : 135.14 = 85.51 : x
  2. Step 2: Convert to fraction form
    97.81/135.14 = 85.51/x
  3. Step 3: Cross multiply
    97.81x = 135.14 × 85.51
  4. Step 4: Simplify right side
    97.81x = 11,554.72
  5. Step 5: Solve for x
    x = 11,554.72/97.81
  6. Step 6: Final answer
    x = 118.14

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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.