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Finding the Fourth Proportional to 286.20, 394.95 and 155.20

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Solution

The fourth proportional to 286.20, 394.95 and 155.20 is: 214.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    286.20 : 394.95 = 155.20 : x
  2. Step 2: Convert to fraction form
    286.20/394.95 = 155.20/x
  3. Step 3: Cross multiply
    286.20x = 394.95 × 155.20
  4. Step 4: Simplify right side
    286.20x = 61,295.46
  5. Step 5: Solve for x
    x = 61,295.46/286.20
  6. Step 6: Final answer
    x = 214.17

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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.