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Finding the Fourth Proportional to 639.34, 958.53 and 330.78

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Solution

The fourth proportional to 639.34, 958.53 and 330.78 is: 495.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.34 : 958.53 = 330.78 : x
  2. Step 2: Convert to fraction form
    639.34/958.53 = 330.78/x
  3. Step 3: Cross multiply
    639.34x = 958.53 × 330.78
  4. Step 4: Simplify right side
    639.34x = 317,062.55
  5. Step 5: Solve for x
    x = 317,062.55/639.34
  6. Step 6: Final answer
    x = 495.92

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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.