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Finding the Fourth Proportional to 103.51, 143.06 and 81.64

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Solution

The fourth proportional to 103.51, 143.06 and 81.64 is: 112.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.51 : 143.06 = 81.64 : x
  2. Step 2: Convert to fraction form
    103.51/143.06 = 81.64/x
  3. Step 3: Cross multiply
    103.51x = 143.06 × 81.64
  4. Step 4: Simplify right side
    103.51x = 11,679.42
  5. Step 5: Solve for x
    x = 11,679.42/103.51
  6. Step 6: Final answer
    x = 112.83

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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.