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Finding the Fourth Proportional to 1,309.01, 1,805.30 and 861.15

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Solution

The fourth proportional to 1,309.01, 1,805.30 and 861.15 is: 1,187.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,309.01 : 1,805.30 = 861.15 : x
  2. Step 2: Convert to fraction form
    1,309.01/1,805.30 = 861.15/x
  3. Step 3: Cross multiply
    1,309.01x = 1,805.30 × 861.15
  4. Step 4: Simplify right side
    1,309.01x = 1,554,634.10
  5. Step 5: Solve for x
    x = 1,554,634.10/1,309.01
  6. Step 6: Final answer
    x = 1,187.64

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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.