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Finding the Fourth Proportional to 642.99, 962.97 and 398.78

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Solution

The fourth proportional to 642.99, 962.97 and 398.78 is: 597.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.99 : 962.97 = 398.78 : x
  2. Step 2: Convert to fraction form
    642.99/962.97 = 398.78/x
  3. Step 3: Cross multiply
    642.99x = 962.97 × 398.78
  4. Step 4: Simplify right side
    642.99x = 384,013.18
  5. Step 5: Solve for x
    x = 384,013.18/642.99
  6. Step 6: Final answer
    x = 597.23

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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.