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Finding the Fourth Proportional to 77.81, 116.39 and 68.49

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Solution

The fourth proportional to 77.81, 116.39 and 68.49 is: 102.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.81 : 116.39 = 68.49 : x
  2. Step 2: Convert to fraction form
    77.81/116.39 = 68.49/x
  3. Step 3: Cross multiply
    77.81x = 116.39 × 68.49
  4. Step 4: Simplify right side
    77.81x = 7,971.21
  5. Step 5: Solve for x
    x = 7,971.21/77.81
  6. Step 6: Final answer
    x = 102.45

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.