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Finding the Fourth Proportional to 105.38, 145.43 and 61.71

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Solution

The fourth proportional to 105.38, 145.43 and 61.71 is: 85.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.38 : 145.43 = 61.71 : x
  2. Step 2: Convert to fraction form
    105.38/145.43 = 61.71/x
  3. Step 3: Cross multiply
    105.38x = 145.43 × 61.71
  4. Step 4: Simplify right side
    105.38x = 8,974.49
  5. Step 5: Solve for x
    x = 8,974.49/105.38
  6. Step 6: Final answer
    x = 85.16

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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.