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Finding the Fourth Proportional to 286.21, 394.96 and 155.21

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Solution

The fourth proportional to 286.21, 394.96 and 155.21 is: 214.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    286.21 : 394.96 = 155.21 : x
  2. Step 2: Convert to fraction form
    286.21/394.96 = 155.21/x
  3. Step 3: Cross multiply
    286.21x = 394.96 × 155.21
  4. Step 4: Simplify right side
    286.21x = 61,301.94
  5. Step 5: Solve for x
    x = 61,301.94/286.21
  6. Step 6: Final answer
    x = 214.19

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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.