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Finding the Fourth Proportional to 1,255.61, 1,884.57 and 639.75

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Solution

The fourth proportional to 1,255.61, 1,884.57 and 639.75 is: 960.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,255.61 : 1,884.57 = 639.75 : x
  2. Step 2: Convert to fraction form
    1,255.61/1,884.57 = 639.75/x
  3. Step 3: Cross multiply
    1,255.61x = 1,884.57 × 639.75
  4. Step 4: Simplify right side
    1,255.61x = 1,205,650.46
  5. Step 5: Solve for x
    x = 1,205,650.46/1,255.61
  6. Step 6: Final answer
    x = 960.21

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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.