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Finding the Fourth Proportional to 66.71, 91.92 and 65.81

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Solution

The fourth proportional to 66.71, 91.92 and 65.81 is: 90.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.71 : 91.92 = 65.81 : x
  2. Step 2: Convert to fraction form
    66.71/91.92 = 65.81/x
  3. Step 3: Cross multiply
    66.71x = 91.92 × 65.81
  4. Step 4: Simplify right side
    66.71x = 6,048.70
  5. Step 5: Solve for x
    x = 6,048.70/66.71
  6. Step 6: Final answer
    x = 90.68

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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.