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Finding the Fourth Proportional to 105.77, 145.90 and 64.31

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Solution

The fourth proportional to 105.77, 145.90 and 64.31 is: 88.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.77 : 145.90 = 64.31 : x
  2. Step 2: Convert to fraction form
    105.77/145.90 = 64.31/x
  3. Step 3: Cross multiply
    105.77x = 145.90 × 64.31
  4. Step 4: Simplify right side
    105.77x = 9,382.83
  5. Step 5: Solve for x
    x = 9,382.83/105.77
  6. Step 6: Final answer
    x = 88.71

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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.