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Finding the Fourth Proportional to 805.59, 1,213.79 and 728.64

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Solution

The fourth proportional to 805.59, 1,213.79 and 728.64 is: 1,097.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.59 : 1,213.79 = 728.64 : x
  2. Step 2: Convert to fraction form
    805.59/1,213.79 = 728.64/x
  3. Step 3: Cross multiply
    805.59x = 1,213.79 × 728.64
  4. Step 4: Simplify right side
    805.59x = 884,415.95
  5. Step 5: Solve for x
    x = 884,415.95/805.59
  6. Step 6: Final answer
    x = 1,097.85

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.