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Finding the Fourth Proportional to 642.21, 885.92 and 380.31

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Solution

The fourth proportional to 642.21, 885.92 and 380.31 is: 524.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.21 : 885.92 = 380.31 : x
  2. Step 2: Convert to fraction form
    642.21/885.92 = 380.31/x
  3. Step 3: Cross multiply
    642.21x = 885.92 × 380.31
  4. Step 4: Simplify right side
    642.21x = 336,922.33
  5. Step 5: Solve for x
    x = 336,922.33/642.21
  6. Step 6: Final answer
    x = 524.63

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.