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Finding the Fourth Proportional to 642.67, 964.42 and 399.36

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Solution

The fourth proportional to 642.67, 964.42 and 399.36 is: 599.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.67 : 964.42 = 399.36 : x
  2. Step 2: Convert to fraction form
    642.67/964.42 = 399.36/x
  3. Step 3: Cross multiply
    642.67x = 964.42 × 399.36
  4. Step 4: Simplify right side
    642.67x = 385,150.77
  5. Step 5: Solve for x
    x = 385,150.77/642.67
  6. Step 6: Final answer
    x = 599.30

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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.