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Finding the Fourth Proportional to 812.61, 1,218.87 and 401.49

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Solution

The fourth proportional to 812.61, 1,218.87 and 401.49 is: 602.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.61 : 1,218.87 = 401.49 : x
  2. Step 2: Convert to fraction form
    812.61/1,218.87 = 401.49/x
  3. Step 3: Cross multiply
    812.61x = 1,218.87 × 401.49
  4. Step 4: Simplify right side
    812.61x = 489,364.12
  5. Step 5: Solve for x
    x = 489,364.12/812.61
  6. Step 6: Final answer
    x = 602.21

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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.