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Finding the Fourth Proportional to 639.97, 959.99 and 207.16

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Solution

The fourth proportional to 639.97, 959.99 and 207.16 is: 310.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.97 : 959.99 = 207.16 : x
  2. Step 2: Convert to fraction form
    639.97/959.99 = 207.16/x
  3. Step 3: Cross multiply
    639.97x = 959.99 × 207.16
  4. Step 4: Simplify right side
    639.97x = 198,868.09
  5. Step 5: Solve for x
    x = 198,868.09/639.97
  6. Step 6: Final answer
    x = 310.75

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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.