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Finding the Fourth Proportional to 1,290.52, 1,934.54 and 640.90

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Solution

The fourth proportional to 1,290.52, 1,934.54 and 640.90 is: 960.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,290.52 : 1,934.54 = 640.90 : x
  2. Step 2: Convert to fraction form
    1,290.52/1,934.54 = 640.90/x
  3. Step 3: Cross multiply
    1,290.52x = 1,934.54 × 640.90
  4. Step 4: Simplify right side
    1,290.52x = 1,239,846.69
  5. Step 5: Solve for x
    x = 1,239,846.69/1,290.52
  6. Step 6: Final answer
    x = 960.73

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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.