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Finding the Fourth Proportional to 642.86, 964.30 and 399.48

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Solution

The fourth proportional to 642.86, 964.30 and 399.48 is: 599.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.86 : 964.30 = 399.48 : x
  2. Step 2: Convert to fraction form
    642.86/964.30 = 399.48/x
  3. Step 3: Cross multiply
    642.86x = 964.30 × 399.48
  4. Step 4: Simplify right side
    642.86x = 385,218.56
  5. Step 5: Solve for x
    x = 385,218.56/642.86
  6. Step 6: Final answer
    x = 599.23

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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.