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Finding the Fourth Proportional to 639.95, 959.95 and 274.49

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Solution

The fourth proportional to 639.95, 959.95 and 274.49 is: 411.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.95 : 959.95 = 274.49 : x
  2. Step 2: Convert to fraction form
    639.95/959.95 = 274.49/x
  3. Step 3: Cross multiply
    639.95x = 959.95 × 274.49
  4. Step 4: Simplify right side
    639.95x = 263,495.82
  5. Step 5: Solve for x
    x = 263,495.82/639.95
  6. Step 6: Final answer
    x = 411.74

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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.