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Finding the Fourth Proportional to 639.12, 957.42 and 330.60

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Solution

The fourth proportional to 639.12, 957.42 and 330.60 is: 495.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.12 : 957.42 = 330.60 : x
  2. Step 2: Convert to fraction form
    639.12/957.42 = 330.60/x
  3. Step 3: Cross multiply
    639.12x = 957.42 × 330.60
  4. Step 4: Simplify right side
    639.12x = 316,523.05
  5. Step 5: Solve for x
    x = 316,523.05/639.12
  6. Step 6: Final answer
    x = 495.25

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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.