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Finding the Fourth Proportional to 66.65, 91.49 and 63.61

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Solution

The fourth proportional to 66.65, 91.49 and 63.61 is: 87.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.65 : 91.49 = 63.61 : x
  2. Step 2: Convert to fraction form
    66.65/91.49 = 63.61/x
  3. Step 3: Cross multiply
    66.65x = 91.49 × 63.61
  4. Step 4: Simplify right side
    66.65x = 5,819.13
  5. Step 5: Solve for x
    x = 5,819.13/66.65
  6. Step 6: Final answer
    x = 87.32

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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.