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Finding the Fourth Proportional to 812.51, 1,217.22 and 421.94

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Solution

The fourth proportional to 812.51, 1,217.22 and 421.94 is: 632.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.51 : 1,217.22 = 421.94 : x
  2. Step 2: Convert to fraction form
    812.51/1,217.22 = 421.94/x
  3. Step 3: Cross multiply
    812.51x = 1,217.22 × 421.94
  4. Step 4: Simplify right side
    812.51x = 513,593.81
  5. Step 5: Solve for x
    x = 513,593.81/812.51
  6. Step 6: Final answer
    x = 632.11

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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.