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Finding the Fourth Proportional to 286.07, 428.85 and 139.73

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Solution

The fourth proportional to 286.07, 428.85 and 139.73 is: 209.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    286.07 : 428.85 = 139.73 : x
  2. Step 2: Convert to fraction form
    286.07/428.85 = 139.73/x
  3. Step 3: Cross multiply
    286.07x = 428.85 × 139.73
  4. Step 4: Simplify right side
    286.07x = 59,922.51
  5. Step 5: Solve for x
    x = 59,922.51/286.07
  6. Step 6: Final answer
    x = 209.47

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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.