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Finding the Fourth Proportional to 1,388, 2,080.38 and 771.41

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Solution

The fourth proportional to 1,388, 2,080.38 and 771.41 is: 1,156.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,388 : 2,080.38 = 771.41 : x
  2. Step 2: Convert to fraction form
    1,388/2,080.38 = 771.41/x
  3. Step 3: Cross multiply
    1,388x = 2,080.38 × 771.41
  4. Step 4: Simplify right side
    1,388x = 1,604,825.94
  5. Step 5: Solve for x
    x = 1,604,825.94/1,388
  6. Step 6: Final answer
    x = 1,156.21

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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.