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Finding the Fourth Proportional to 66.05, 91.14 and 39.81

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Solution

The fourth proportional to 66.05, 91.14 and 39.81 is: 54.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.05 : 91.14 = 39.81 : x
  2. Step 2: Convert to fraction form
    66.05/91.14 = 39.81/x
  3. Step 3: Cross multiply
    66.05x = 91.14 × 39.81
  4. Step 4: Simplify right side
    66.05x = 3,628.28
  5. Step 5: Solve for x
    x = 3,628.28/66.05
  6. Step 6: Final answer
    x = 54.93

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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.