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Finding the Fourth Proportional to 105.74, 145.76 and 78.14

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Solution

The fourth proportional to 105.74, 145.76 and 78.14 is: 107.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.74 : 145.76 = 78.14 : x
  2. Step 2: Convert to fraction form
    105.74/145.76 = 78.14/x
  3. Step 3: Cross multiply
    105.74x = 145.76 × 78.14
  4. Step 4: Simplify right side
    105.74x = 11,389.69
  5. Step 5: Solve for x
    x = 11,389.69/105.74
  6. Step 6: Final answer
    x = 107.71

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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.