Home / 1,309.20-1,805.66-811.55

Finding the Fourth Proportional to 1,309.20, 1,805.66 and 811.55

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Solution

The fourth proportional to 1,309.20, 1,805.66 and 811.55 is: 1,119.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,309.20 : 1,805.66 = 811.55 : x
  2. Step 2: Convert to fraction form
    1,309.20/1,805.66 = 811.55/x
  3. Step 3: Cross multiply
    1,309.20x = 1,805.66 × 811.55
  4. Step 4: Simplify right side
    1,309.20x = 1,465,389.92
  5. Step 5: Solve for x
    x = 1,465,389.92/1,309.20
  6. Step 6: Final answer
    x = 1,119.31

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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.