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Finding the Fourth Proportional to 664.45, 995.85 and 420.43

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Solution

The fourth proportional to 664.45, 995.85 and 420.43 is: 630.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    664.45 : 995.85 = 420.43 : x
  2. Step 2: Convert to fraction form
    664.45/995.85 = 420.43/x
  3. Step 3: Cross multiply
    664.45x = 995.85 × 420.43
  4. Step 4: Simplify right side
    664.45x = 418,685.22
  5. Step 5: Solve for x
    x = 418,685.22/664.45
  6. Step 6: Final answer
    x = 630.12

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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.