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Finding the Fourth Proportional to 639.78, 959.52 and 274.74

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Solution

The fourth proportional to 639.78, 959.52 and 274.74 is: 412.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.78 : 959.52 = 274.74 : x
  2. Step 2: Convert to fraction form
    639.78/959.52 = 274.74/x
  3. Step 3: Cross multiply
    639.78x = 959.52 × 274.74
  4. Step 4: Simplify right side
    639.78x = 263,618.52
  5. Step 5: Solve for x
    x = 263,618.52/639.78
  6. Step 6: Final answer
    x = 412.05

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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.