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Finding the Fourth Proportional to 286.05, 428.94 and 90.99

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Solution

The fourth proportional to 286.05, 428.94 and 90.99 is: 136.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    286.05 : 428.94 = 90.99 : x
  2. Step 2: Convert to fraction form
    286.05/428.94 = 90.99/x
  3. Step 3: Cross multiply
    286.05x = 428.94 × 90.99
  4. Step 4: Simplify right side
    286.05x = 39,029.25
  5. Step 5: Solve for x
    x = 39,029.25/286.05
  6. Step 6: Final answer
    x = 136.44

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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.