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Finding the Fourth Proportional to 664.35, 995.67 and 390.57

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Solution

The fourth proportional to 664.35, 995.67 and 390.57 is: 585.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    664.35 : 995.67 = 390.57 : x
  2. Step 2: Convert to fraction form
    664.35/995.67 = 390.57/x
  3. Step 3: Cross multiply
    664.35x = 995.67 × 390.57
  4. Step 4: Simplify right side
    664.35x = 388,878.83
  5. Step 5: Solve for x
    x = 388,878.83/664.35
  6. Step 6: Final answer
    x = 585.35

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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.