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Finding the Fourth Proportional to 639.68, 959.46 and 274.40

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Solution

The fourth proportional to 639.68, 959.46 and 274.40 is: 411.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.68 : 959.46 = 274.40 : x
  2. Step 2: Convert to fraction form
    639.68/959.46 = 274.40/x
  3. Step 3: Cross multiply
    639.68x = 959.46 × 274.40
  4. Step 4: Simplify right side
    639.68x = 263,275.82
  5. Step 5: Solve for x
    x = 263,275.82/639.68
  6. Step 6: Final answer
    x = 411.57

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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.