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Finding the Fourth Proportional to 2,138, 3,207 and 770

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Solution

The fourth proportional to 2,138, 3,207 and 770 is: 1,155

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,138 : 3,207 = 770 : x
  2. Step 2: Convert to fraction form
    2,138/3,207 = 770/x
  3. Step 3: Cross multiply
    2,138x = 3,207 × 770
  4. Step 4: Simplify right side
    2,138x = 2,469,390
  5. Step 5: Solve for x
    x = 2,469,390/2,138
  6. Step 6: Final answer
    x = 1,155

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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.