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Finding the Fourth Proportional to 812.71, 1,219.20 and 401.89

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Solution

The fourth proportional to 812.71, 1,219.20 and 401.89 is: 602.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.71 : 1,219.20 = 401.89 : x
  2. Step 2: Convert to fraction form
    812.71/1,219.20 = 401.89/x
  3. Step 3: Cross multiply
    812.71x = 1,219.20 × 401.89
  4. Step 4: Simplify right side
    812.71x = 489,984.29
  5. Step 5: Solve for x
    x = 489,984.29/812.71
  6. Step 6: Final answer
    x = 602.90

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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.