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Finding the Fourth Proportional to 642.59, 886.62 and 393.82

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Solution

The fourth proportional to 642.59, 886.62 and 393.82 is: 543.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.59 : 886.62 = 393.82 : x
  2. Step 2: Convert to fraction form
    642.59/886.62 = 393.82/x
  3. Step 3: Cross multiply
    642.59x = 886.62 × 393.82
  4. Step 4: Simplify right side
    642.59x = 349,168.69
  5. Step 5: Solve for x
    x = 349,168.69/642.59
  6. Step 6: Final answer
    x = 543.38

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.