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Finding the Fourth Proportional to 641.21, 960.12 and 393.89

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Solution

The fourth proportional to 641.21, 960.12 and 393.89 is: 589.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.21 : 960.12 = 393.89 : x
  2. Step 2: Convert to fraction form
    641.21/960.12 = 393.89/x
  3. Step 3: Cross multiply
    641.21x = 960.12 × 393.89
  4. Step 4: Simplify right side
    641.21x = 378,176.87
  5. Step 5: Solve for x
    x = 378,176.87/641.21
  6. Step 6: Final answer
    x = 589.79

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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.