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Finding the Fourth Proportional to 1,389.09, 2,084.79 and 731.20

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Solution

The fourth proportional to 1,389.09, 2,084.79 and 731.20 is: 1,097.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,389.09 : 2,084.79 = 731.20 : x
  2. Step 2: Convert to fraction form
    1,389.09/2,084.79 = 731.20/x
  3. Step 3: Cross multiply
    1,389.09x = 2,084.79 × 731.20
  4. Step 4: Simplify right side
    1,389.09x = 1,524,398.45
  5. Step 5: Solve for x
    x = 1,524,398.45/1,389.09
  6. Step 6: Final answer
    x = 1,097.41

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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.