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Finding the Fourth Proportional to 1,309, 1,805.34 and 784.12

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Solution

The fourth proportional to 1,309, 1,805.34 and 784.12 is: 1,081.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,309 : 1,805.34 = 784.12 : x
  2. Step 2: Convert to fraction form
    1,309/1,805.34 = 784.12/x
  3. Step 3: Cross multiply
    1,309x = 1,805.34 × 784.12
  4. Step 4: Simplify right side
    1,309x = 1,415,603.20
  5. Step 5: Solve for x
    x = 1,415,603.20/1,309
  6. Step 6: Final answer
    x = 1,081.44

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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.