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Finding the Fourth Proportional to 663.38, 993.98 and 389.42

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Solution

The fourth proportional to 663.38, 993.98 and 389.42 is: 583.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    663.38 : 993.98 = 389.42 : x
  2. Step 2: Convert to fraction form
    663.38/993.98 = 389.42/x
  3. Step 3: Cross multiply
    663.38x = 993.98 × 389.42
  4. Step 4: Simplify right side
    663.38x = 387,075.69
  5. Step 5: Solve for x
    x = 387,075.69/663.38
  6. Step 6: Final answer
    x = 583.49

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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.