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Finding the Fourth Proportional to 105.21, 145.22 and 66.38

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Solution

The fourth proportional to 105.21, 145.22 and 66.38 is: 91.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.21 : 145.22 = 66.38 : x
  2. Step 2: Convert to fraction form
    105.21/145.22 = 66.38/x
  3. Step 3: Cross multiply
    105.21x = 145.22 × 66.38
  4. Step 4: Simplify right side
    105.21x = 9,638.65
  5. Step 5: Solve for x
    x = 9,638.65/105.21
  6. Step 6: Final answer
    x = 91.61

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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.