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Finding the Fourth Proportional to 857.38, 1,285.31 and 412.39

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Solution

The fourth proportional to 857.38, 1,285.31 and 412.39 is: 618.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.38 : 1,285.31 = 412.39 : x
  2. Step 2: Convert to fraction form
    857.38/1,285.31 = 412.39/x
  3. Step 3: Cross multiply
    857.38x = 1,285.31 × 412.39
  4. Step 4: Simplify right side
    857.38x = 530,042.56
  5. Step 5: Solve for x
    x = 530,042.56/857.38
  6. Step 6: Final answer
    x = 618.21

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1.5x scale

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.