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Finding the Fourth Proportional to 857.87, 1,286.78 and 272.90

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Solution

The fourth proportional to 857.87, 1,286.78 and 272.90 is: 409.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.87 : 1,286.78 = 272.90 : x
  2. Step 2: Convert to fraction form
    857.87/1,286.78 = 272.90/x
  3. Step 3: Cross multiply
    857.87x = 1,286.78 × 272.90
  4. Step 4: Simplify right side
    857.87x = 351,164.89
  5. Step 5: Solve for x
    x = 351,164.89/857.87
  6. Step 6: Final answer
    x = 409.35

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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.