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Finding the Fourth Proportional to 105.31, 145.26 and 77.75

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Solution

The fourth proportional to 105.31, 145.26 and 77.75 is: 107.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.31 : 145.26 = 77.75 : x
  2. Step 2: Convert to fraction form
    105.31/145.26 = 77.75/x
  3. Step 3: Cross multiply
    105.31x = 145.26 × 77.75
  4. Step 4: Simplify right side
    105.31x = 11,293.97
  5. Step 5: Solve for x
    x = 11,293.97/105.31
  6. Step 6: Final answer
    x = 107.24

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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.