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Finding the Fourth Proportional to 1,379.88, 2,069.32 and 405.68

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Solution

The fourth proportional to 1,379.88, 2,069.32 and 405.68 is: 608.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,379.88 : 2,069.32 = 405.68 : x
  2. Step 2: Convert to fraction form
    1,379.88/2,069.32 = 405.68/x
  3. Step 3: Cross multiply
    1,379.88x = 2,069.32 × 405.68
  4. Step 4: Simplify right side
    1,379.88x = 839,481.74
  5. Step 5: Solve for x
    x = 839,481.74/1,379.88
  6. Step 6: Final answer
    x = 608.37

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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.