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Finding the Fourth Proportional to 812.85, 1,218.64 and 401.70

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Solution

The fourth proportional to 812.85, 1,218.64 and 401.70 is: 602.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.85 : 1,218.64 = 401.70 : x
  2. Step 2: Convert to fraction form
    812.85/1,218.64 = 401.70/x
  3. Step 3: Cross multiply
    812.85x = 1,218.64 × 401.70
  4. Step 4: Simplify right side
    812.85x = 489,527.69
  5. Step 5: Solve for x
    x = 489,527.69/812.85
  6. Step 6: Final answer
    x = 602.24

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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.