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Finding the Fourth Proportional to 857.11, 1,285 and 394.56

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Solution

The fourth proportional to 857.11, 1,285 and 394.56 is: 591.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.11 : 1,285 = 394.56 : x
  2. Step 2: Convert to fraction form
    857.11/1,285 = 394.56/x
  3. Step 3: Cross multiply
    857.11x = 1,285 × 394.56
  4. Step 4: Simplify right side
    857.11x = 507,009.60
  5. Step 5: Solve for x
    x = 507,009.60/857.11
  6. Step 6: Final answer
    x = 591.53

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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.