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Finding the Fourth Proportional to 642.33, 963.29 and 438.21

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Solution

The fourth proportional to 642.33, 963.29 and 438.21 is: 657.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.33 : 963.29 = 438.21 : x
  2. Step 2: Convert to fraction form
    642.33/963.29 = 438.21/x
  3. Step 3: Cross multiply
    642.33x = 963.29 × 438.21
  4. Step 4: Simplify right side
    642.33x = 422,124.41
  5. Step 5: Solve for x
    x = 422,124.41/642.33
  6. Step 6: Final answer
    x = 657.18

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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.