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Finding the Fourth Proportional to 105.31, 145.36 and 63.90

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Solution

The fourth proportional to 105.31, 145.36 and 63.90 is: 88.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.31 : 145.36 = 63.90 : x
  2. Step 2: Convert to fraction form
    105.31/145.36 = 63.90/x
  3. Step 3: Cross multiply
    105.31x = 145.36 × 63.90
  4. Step 4: Simplify right side
    105.31x = 9,288.50
  5. Step 5: Solve for x
    x = 9,288.50/105.31
  6. Step 6: Final answer
    x = 88.20

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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.