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Finding the Fourth Proportional to 190.45, 285.47 and 139.31

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Solution

The fourth proportional to 190.45, 285.47 and 139.31 is: 208.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    190.45 : 285.47 = 139.31 : x
  2. Step 2: Convert to fraction form
    190.45/285.47 = 139.31/x
  3. Step 3: Cross multiply
    190.45x = 285.47 × 139.31
  4. Step 4: Simplify right side
    190.45x = 39,766.70
  5. Step 5: Solve for x
    x = 39,766.70/190.45
  6. Step 6: Final answer
    x = 208.81

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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.