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Finding the Fourth Proportional to 812.93, 1,219.40 and 380.39

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Solution

The fourth proportional to 812.93, 1,219.40 and 380.39 is: 570.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.93 : 1,219.40 = 380.39 : x
  2. Step 2: Convert to fraction form
    812.93/1,219.40 = 380.39/x
  3. Step 3: Cross multiply
    812.93x = 1,219.40 × 380.39
  4. Step 4: Simplify right side
    812.93x = 463,845.66
  5. Step 5: Solve for x
    x = 463,845.66/812.93
  6. Step 6: Final answer
    x = 570.59

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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.