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Finding the Fourth Proportional to 190.78, 286.21 and 69.05

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Solution

The fourth proportional to 190.78, 286.21 and 69.05 is: 103.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    190.78 : 286.21 = 69.05 : x
  2. Step 2: Convert to fraction form
    190.78/286.21 = 69.05/x
  3. Step 3: Cross multiply
    190.78x = 286.21 × 69.05
  4. Step 4: Simplify right side
    190.78x = 19,762.80
  5. Step 5: Solve for x
    x = 19,762.80/190.78
  6. Step 6: Final answer
    x = 103.59

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.