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Finding the Fourth Proportional to 105.46, 145.56 and 61.81

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Solution

The fourth proportional to 105.46, 145.56 and 61.81 is: 85.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.46 : 145.56 = 61.81 : x
  2. Step 2: Convert to fraction form
    105.46/145.56 = 61.81/x
  3. Step 3: Cross multiply
    105.46x = 145.56 × 61.81
  4. Step 4: Simplify right side
    105.46x = 8,997.06
  5. Step 5: Solve for x
    x = 8,997.06/105.46
  6. Step 6: Final answer
    x = 85.31

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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.