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Finding the Fourth Proportional to 805.81, 1,208.40 and 343.80

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Solution

The fourth proportional to 805.81, 1,208.40 and 343.80 is: 515.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.81 : 1,208.40 = 343.80 : x
  2. Step 2: Convert to fraction form
    805.81/1,208.40 = 343.80/x
  3. Step 3: Cross multiply
    805.81x = 1,208.40 × 343.80
  4. Step 4: Simplify right side
    805.81x = 415,447.92
  5. Step 5: Solve for x
    x = 415,447.92/805.81
  6. Step 6: Final answer
    x = 515.57

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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.