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Finding the Fourth Proportional to 812.20, 1,208.55 and 809.46

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Solution

The fourth proportional to 812.20, 1,208.55 and 809.46 is: 1,204.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.20 : 1,208.55 = 809.46 : x
  2. Step 2: Convert to fraction form
    812.20/1,208.55 = 809.46/x
  3. Step 3: Cross multiply
    812.20x = 1,208.55 × 809.46
  4. Step 4: Simplify right side
    812.20x = 978,268.84
  5. Step 5: Solve for x
    x = 978,268.84/812.20
  6. Step 6: Final answer
    x = 1,204.47

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.