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Finding the Fourth Proportional to 639.18, 957.15 and 394.97

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Solution

The fourth proportional to 639.18, 957.15 and 394.97 is: 591.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.18 : 957.15 = 394.97 : x
  2. Step 2: Convert to fraction form
    639.18/957.15 = 394.97/x
  3. Step 3: Cross multiply
    639.18x = 957.15 × 394.97
  4. Step 4: Simplify right side
    639.18x = 378,040.75
  5. Step 5: Solve for x
    x = 378,040.75/639.18
  6. Step 6: Final answer
    x = 591.45

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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.