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Finding the Fourth Proportional to 1,309.31, 1,806.81 and 711.80

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Solution

The fourth proportional to 1,309.31, 1,806.81 and 711.80 is: 982.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,309.31 : 1,806.81 = 711.80 : x
  2. Step 2: Convert to fraction form
    1,309.31/1,806.81 = 711.80/x
  3. Step 3: Cross multiply
    1,309.31x = 1,806.81 × 711.80
  4. Step 4: Simplify right side
    1,309.31x = 1,286,078.32
  5. Step 5: Solve for x
    x = 1,286,078.32/1,309.31
  6. Step 6: Final answer
    x = 982.26

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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.