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Finding the Fourth Proportional to 642.38, 964.05 and 399.26

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Solution

The fourth proportional to 642.38, 964.05 and 399.26 is: 599.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.38 : 964.05 = 399.26 : x
  2. Step 2: Convert to fraction form
    642.38/964.05 = 399.26/x
  3. Step 3: Cross multiply
    642.38x = 964.05 × 399.26
  4. Step 4: Simplify right side
    642.38x = 384,906.60
  5. Step 5: Solve for x
    x = 384,906.60/642.38
  6. Step 6: Final answer
    x = 599.19

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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.