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Finding the Fourth Proportional to 105.84, 145.94 and 78.30

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Solution

The fourth proportional to 105.84, 145.94 and 78.30 is: 107.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.84 : 145.94 = 78.30 : x
  2. Step 2: Convert to fraction form
    105.84/145.94 = 78.30/x
  3. Step 3: Cross multiply
    105.84x = 145.94 × 78.30
  4. Step 4: Simplify right side
    105.84x = 11,426.71
  5. Step 5: Solve for x
    x = 11,426.71/105.84
  6. Step 6: Final answer
    x = 107.96

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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.