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Finding the Fourth Proportional to 1,309.18, 1,805.77 and 811.30

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Solution

The fourth proportional to 1,309.18, 1,805.77 and 811.30 is: 1,119.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,309.18 : 1,805.77 = 811.30 : x
  2. Step 2: Convert to fraction form
    1,309.18/1,805.77 = 811.30/x
  3. Step 3: Cross multiply
    1,309.18x = 1,805.77 × 811.30
  4. Step 4: Simplify right side
    1,309.18x = 1,465,021.20
  5. Step 5: Solve for x
    x = 1,465,021.20/1,309.18
  6. Step 6: Final answer
    x = 1,119.04

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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.