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Finding the Fourth Proportional to 857.67, 1,285.49 and 419.13

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Solution

The fourth proportional to 857.67, 1,285.49 and 419.13 is: 628.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.67 : 1,285.49 = 419.13 : x
  2. Step 2: Convert to fraction form
    857.67/1,285.49 = 419.13/x
  3. Step 3: Cross multiply
    857.67x = 1,285.49 × 419.13
  4. Step 4: Simplify right side
    857.67x = 538,785.33
  5. Step 5: Solve for x
    x = 538,785.33/857.67
  6. Step 6: Final answer
    x = 628.20

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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.