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Finding the Fourth Proportional to 664.40, 995.88 and 390.62

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Solution

The fourth proportional to 664.40, 995.88 and 390.62 is: 585.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    664.40 : 995.88 = 390.62 : x
  2. Step 2: Convert to fraction form
    664.40/995.88 = 390.62/x
  3. Step 3: Cross multiply
    664.40x = 995.88 × 390.62
  4. Step 4: Simplify right side
    664.40x = 389,010.65
  5. Step 5: Solve for x
    x = 389,010.65/664.40
  6. Step 6: Final answer
    x = 585.51

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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.