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Finding the Fourth Proportional to 511.20, 705.40 and 287.10

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Solution

The fourth proportional to 511.20, 705.40 and 287.10 is: 396.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    511.20 : 705.40 = 287.10 : x
  2. Step 2: Convert to fraction form
    511.20/705.40 = 287.10/x
  3. Step 3: Cross multiply
    511.20x = 705.40 × 287.10
  4. Step 4: Simplify right side
    511.20x = 202,520.34
  5. Step 5: Solve for x
    x = 202,520.34/511.20
  6. Step 6: Final answer
    x = 396.17

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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.