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Finding the Fourth Proportional to 812.90, 1,218.90 and 379.52

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Solution

The fourth proportional to 812.90, 1,218.90 and 379.52 is: 569.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.90 : 1,218.90 = 379.52 : x
  2. Step 2: Convert to fraction form
    812.90/1,218.90 = 379.52/x
  3. Step 3: Cross multiply
    812.90x = 1,218.90 × 379.52
  4. Step 4: Simplify right side
    812.90x = 462,596.93
  5. Step 5: Solve for x
    x = 462,596.93/812.90
  6. Step 6: Final answer
    x = 569.07

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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.