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Finding the Fourth Proportional to 857.15, 1,285.82 and 394.91

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Solution

The fourth proportional to 857.15, 1,285.82 and 394.91 is: 592.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.15 : 1,285.82 = 394.91 : x
  2. Step 2: Convert to fraction form
    857.15/1,285.82 = 394.91/x
  3. Step 3: Cross multiply
    857.15x = 1,285.82 × 394.91
  4. Step 4: Simplify right side
    857.15x = 507,783.18
  5. Step 5: Solve for x
    x = 507,783.18/857.15
  6. Step 6: Final answer
    x = 592.41

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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.