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Finding the Fourth Proportional to 842.13, 1,261.35 and 408.38

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Solution

The fourth proportional to 842.13, 1,261.35 and 408.38 is: 611.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    842.13 : 1,261.35 = 408.38 : x
  2. Step 2: Convert to fraction form
    842.13/1,261.35 = 408.38/x
  3. Step 3: Cross multiply
    842.13x = 1,261.35 × 408.38
  4. Step 4: Simplify right side
    842.13x = 515,103.81
  5. Step 5: Solve for x
    x = 515,103.81/842.13
  6. Step 6: Final answer
    x = 611.67

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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.