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Finding the Fourth Proportional to 427.89, 641.84 and 139.33

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Solution

The fourth proportional to 427.89, 641.84 and 139.33 is: 209.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.89 : 641.84 = 139.33 : x
  2. Step 2: Convert to fraction form
    427.89/641.84 = 139.33/x
  3. Step 3: Cross multiply
    427.89x = 641.84 × 139.33
  4. Step 4: Simplify right side
    427.89x = 89,427.57
  5. Step 5: Solve for x
    x = 89,427.57/427.89
  6. Step 6: Final answer
    x = 209.00

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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.