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Finding the Fourth Proportional to 642.42, 964.05 and 399.11

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Solution

The fourth proportional to 642.42, 964.05 and 399.11 is: 598.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.42 : 964.05 = 399.11 : x
  2. Step 2: Convert to fraction form
    642.42/964.05 = 399.11/x
  3. Step 3: Cross multiply
    642.42x = 964.05 × 399.11
  4. Step 4: Simplify right side
    642.42x = 384,764.41
  5. Step 5: Solve for x
    x = 384,764.41/642.42
  6. Step 6: Final answer
    x = 598.93

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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.