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Finding the Fourth Proportional to 66.45, 91.16 and 63.65

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Solution

The fourth proportional to 66.45, 91.16 and 63.65 is: 87.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.45 : 91.16 = 63.65 : x
  2. Step 2: Convert to fraction form
    66.45/91.16 = 63.65/x
  3. Step 3: Cross multiply
    66.45x = 91.16 × 63.65
  4. Step 4: Simplify right side
    66.45x = 5,802.02
  5. Step 5: Solve for x
    x = 5,802.02/66.45
  6. Step 6: Final answer
    x = 87.31

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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.