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Finding the Fourth Proportional to 105.31, 145.37 and 80.81

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Solution

The fourth proportional to 105.31, 145.37 and 80.81 is: 111.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.31 : 145.37 = 80.81 : x
  2. Step 2: Convert to fraction form
    105.31/145.37 = 80.81/x
  3. Step 3: Cross multiply
    105.31x = 145.37 × 80.81
  4. Step 4: Simplify right side
    105.31x = 11,746.22
  5. Step 5: Solve for x
    x = 11,746.22/105.31
  6. Step 6: Final answer
    x = 111.54

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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.