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Finding the Fourth Proportional to 842.05, 1,263.21 and 379.81

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Solution

The fourth proportional to 842.05, 1,263.21 and 379.81 is: 569.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    842.05 : 1,263.21 = 379.81 : x
  2. Step 2: Convert to fraction form
    842.05/1,263.21 = 379.81/x
  3. Step 3: Cross multiply
    842.05x = 1,263.21 × 379.81
  4. Step 4: Simplify right side
    842.05x = 479,783.74
  5. Step 5: Solve for x
    x = 479,783.74/842.05
  6. Step 6: Final answer
    x = 569.78

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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.