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Finding the Fourth Proportional to 682.38, 1,021.50 and 643.95

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Solution

The fourth proportional to 682.38, 1,021.50 and 643.95 is: 963.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    682.38 : 1,021.50 = 643.95 : x
  2. Step 2: Convert to fraction form
    682.38/1,021.50 = 643.95/x
  3. Step 3: Cross multiply
    682.38x = 1,021.50 × 643.95
  4. Step 4: Simplify right side
    682.38x = 657,794.93
  5. Step 5: Solve for x
    x = 657,794.93/682.38
  6. Step 6: Final answer
    x = 963.97

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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.