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Finding the Fourth Proportional to 805.36, 1,209.11 and 690.55

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Solution

The fourth proportional to 805.36, 1,209.11 and 690.55 is: 1,036.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.36 : 1,209.11 = 690.55 : x
  2. Step 2: Convert to fraction form
    805.36/1,209.11 = 690.55/x
  3. Step 3: Cross multiply
    805.36x = 1,209.11 × 690.55
  4. Step 4: Simplify right side
    805.36x = 834,950.91
  5. Step 5: Solve for x
    x = 834,950.91/805.36
  6. Step 6: Final answer
    x = 1,036.74

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.