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Finding the Fourth Proportional to 66.51, 91.17 and 65.57

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Solution

The fourth proportional to 66.51, 91.17 and 65.57 is: 89.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.51 : 91.17 = 65.57 : x
  2. Step 2: Convert to fraction form
    66.51/91.17 = 65.57/x
  3. Step 3: Cross multiply
    66.51x = 91.17 × 65.57
  4. Step 4: Simplify right side
    66.51x = 5,977.56
  5. Step 5: Solve for x
    x = 5,977.56/66.51
  6. Step 6: Final answer
    x = 89.87

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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.