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Finding the Fourth Proportional to 1,309.21, 1,806.73 and 719.78

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Solution

The fourth proportional to 1,309.21, 1,806.73 and 719.78 is: 993.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,309.21 : 1,806.73 = 719.78 : x
  2. Step 2: Convert to fraction form
    1,309.21/1,806.73 = 719.78/x
  3. Step 3: Cross multiply
    1,309.21x = 1,806.73 × 719.78
  4. Step 4: Simplify right side
    1,309.21x = 1,300,448.12
  5. Step 5: Solve for x
    x = 1,300,448.12/1,309.21
  6. Step 6: Final answer
    x = 993.31

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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.