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Finding the Fourth Proportional to 993.40, 1,490.20 and 408.65

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Solution

The fourth proportional to 993.40, 1,490.20 and 408.65 is: 613.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    993.40 : 1,490.20 = 408.65 : x
  2. Step 2: Convert to fraction form
    993.40/1,490.20 = 408.65/x
  3. Step 3: Cross multiply
    993.40x = 1,490.20 × 408.65
  4. Step 4: Simplify right side
    993.40x = 608,961.76
  5. Step 5: Solve for x
    x = 608,961.76/993.40
  6. Step 6: Final answer
    x = 613.01

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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.