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Finding the Fourth Proportional to 669.11, 1,003.79 and 258.21

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Solution

The fourth proportional to 669.11, 1,003.79 and 258.21 is: 387.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.11 : 1,003.79 = 258.21 : x
  2. Step 2: Convert to fraction form
    669.11/1,003.79 = 258.21/x
  3. Step 3: Cross multiply
    669.11x = 1,003.79 × 258.21
  4. Step 4: Simplify right side
    669.11x = 259,182.31
  5. Step 5: Solve for x
    x = 259,182.31/669.11
  6. Step 6: Final answer
    x = 387.36

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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.