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Finding the Fourth Proportional to 2,138.39, 3,207.90 and 905.80

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Solution

The fourth proportional to 2,138.39, 3,207.90 and 905.80 is: 1,358.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,138.39 : 3,207.90 = 905.80 : x
  2. Step 2: Convert to fraction form
    2,138.39/3,207.90 = 905.80/x
  3. Step 3: Cross multiply
    2,138.39x = 3,207.90 × 905.80
  4. Step 4: Simplify right side
    2,138.39x = 2,905,715.82
  5. Step 5: Solve for x
    x = 2,905,715.82/2,138.39
  6. Step 6: Final answer
    x = 1,358.84

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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.