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Finding the Fourth Proportional to 105.29, 145.28 and 77.69

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Solution

The fourth proportional to 105.29, 145.28 and 77.69 is: 107.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.29 : 145.28 = 77.69 : x
  2. Step 2: Convert to fraction form
    105.29/145.28 = 77.69/x
  3. Step 3: Cross multiply
    105.29x = 145.28 × 77.69
  4. Step 4: Simplify right side
    105.29x = 11,286.80
  5. Step 5: Solve for x
    x = 11,286.80/105.29
  6. Step 6: Final answer
    x = 107.20

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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.