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Finding the Fourth Proportional to 1,389.12, 1,917.18 and 799.65

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Solution

The fourth proportional to 1,389.12, 1,917.18 and 799.65 is: 1,103.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,389.12 : 1,917.18 = 799.65 : x
  2. Step 2: Convert to fraction form
    1,389.12/1,917.18 = 799.65/x
  3. Step 3: Cross multiply
    1,389.12x = 1,917.18 × 799.65
  4. Step 4: Simplify right side
    1,389.12x = 1,533,072.99
  5. Step 5: Solve for x
    x = 1,533,072.99/1,389.12
  6. Step 6: Final answer
    x = 1,103.63

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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.