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Finding the Fourth Proportional to 972.41, 1,340.90 and 640.41

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Solution

The fourth proportional to 972.41, 1,340.90 and 640.41 is: 883.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    972.41 : 1,340.90 = 640.41 : x
  2. Step 2: Convert to fraction form
    972.41/1,340.90 = 640.41/x
  3. Step 3: Cross multiply
    972.41x = 1,340.90 × 640.41
  4. Step 4: Simplify right side
    972.41x = 858,723.54
  5. Step 5: Solve for x
    x = 858,723.54/972.41
  6. Step 6: Final answer
    x = 883.09

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.