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Finding the Fourth Proportional to 2,139.40, 3,206.40 and 1,907.20

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Solution

The fourth proportional to 2,139.40, 3,206.40 and 1,907.20 is: 2,858.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,139.40 : 3,206.40 = 1,907.20 : x
  2. Step 2: Convert to fraction form
    2,139.40/3,206.40 = 1,907.20/x
  3. Step 3: Cross multiply
    2,139.40x = 3,206.40 × 1,907.20
  4. Step 4: Simplify right side
    2,139.40x = 6,115,246.08
  5. Step 5: Solve for x
    x = 6,115,246.08/2,139.40
  6. Step 6: Final answer
    x = 2,858.39

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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.