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Finding the Fourth Proportional to 68.81, 94.34 and 66.78

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Solution

The fourth proportional to 68.81, 94.34 and 66.78 is: 91.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    68.81 : 94.34 = 66.78 : x
  2. Step 2: Convert to fraction form
    68.81/94.34 = 66.78/x
  3. Step 3: Cross multiply
    68.81x = 94.34 × 66.78
  4. Step 4: Simplify right side
    68.81x = 6,300.19
  5. Step 5: Solve for x
    x = 6,300.19/68.81
  6. Step 6: Final answer
    x = 91.57

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.