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Finding the Fourth Proportional to 1,309.31, 1,806.85 and 778.46

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Solution

The fourth proportional to 1,309.31, 1,806.85 and 778.46 is: 1,074.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,309.31 : 1,806.85 = 778.46 : x
  2. Step 2: Convert to fraction form
    1,309.31/1,806.85 = 778.46/x
  3. Step 3: Cross multiply
    1,309.31x = 1,806.85 × 778.46
  4. Step 4: Simplify right side
    1,309.31x = 1,406,553.99
  5. Step 5: Solve for x
    x = 1,406,553.99/1,309.31
  6. Step 6: Final answer
    x = 1,074.27

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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.