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Finding the Fourth Proportional to 663.49, 994.42 and 389.78

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Solution

The fourth proportional to 663.49, 994.42 and 389.78 is: 584.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    663.49 : 994.42 = 389.78 : x
  2. Step 2: Convert to fraction form
    663.49/994.42 = 389.78/x
  3. Step 3: Cross multiply
    663.49x = 994.42 × 389.78
  4. Step 4: Simplify right side
    663.49x = 387,605.03
  5. Step 5: Solve for x
    x = 387,605.03/663.49
  6. Step 6: Final answer
    x = 584.19

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1.5x scale

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.