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Finding the Fourth Proportional to 663.60, 995.40 and 389.55

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Solution

The fourth proportional to 663.60, 995.40 and 389.55 is: 584.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    663.60 : 995.40 = 389.55 : x
  2. Step 2: Convert to fraction form
    663.60/995.40 = 389.55/x
  3. Step 3: Cross multiply
    663.60x = 995.40 × 389.55
  4. Step 4: Simplify right side
    663.60x = 387,758.07
  5. Step 5: Solve for x
    x = 387,758.07/663.60
  6. Step 6: Final answer
    x = 584.33

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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.