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Finding the Fourth Proportional to 857.78, 1,286.40 and 272.77

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Solution

The fourth proportional to 857.78, 1,286.40 and 272.77 is: 409.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.78 : 1,286.40 = 272.77 : x
  2. Step 2: Convert to fraction form
    857.78/1,286.40 = 272.77/x
  3. Step 3: Cross multiply
    857.78x = 1,286.40 × 272.77
  4. Step 4: Simplify right side
    857.78x = 350,891.33
  5. Step 5: Solve for x
    x = 350,891.33/857.78
  6. Step 6: Final answer
    x = 409.07

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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.