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Finding the Fourth Proportional to 102.80, 141.93 and 81.23

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Solution

The fourth proportional to 102.80, 141.93 and 81.23 is: 112.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.80 : 141.93 = 81.23 : x
  2. Step 2: Convert to fraction form
    102.80/141.93 = 81.23/x
  3. Step 3: Cross multiply
    102.80x = 141.93 × 81.23
  4. Step 4: Simplify right side
    102.80x = 11,528.26
  5. Step 5: Solve for x
    x = 11,528.26/102.80
  6. Step 6: Final answer
    x = 112.14

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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.