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Finding the Fourth Proportional to 1,940.78, 2,911.22 and 642.25

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Solution

The fourth proportional to 1,940.78, 2,911.22 and 642.25 is: 963.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,940.78 : 2,911.22 = 642.25 : x
  2. Step 2: Convert to fraction form
    1,940.78/2,911.22 = 642.25/x
  3. Step 3: Cross multiply
    1,940.78x = 2,911.22 × 642.25
  4. Step 4: Simplify right side
    1,940.78x = 1,869,731.05
  5. Step 5: Solve for x
    x = 1,869,731.05/1,940.78
  6. Step 6: Final answer
    x = 963.39

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1.5x scale

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.