Question Completion:
Demographic Data on Market Segments
Segment                         Market   Growth   Purchase   Average
                                           Size        Rate     Behavior      Price   
Urban Commuters       20,000         3%          23%        $45.00
School Children            35,000         1%          20%        $24.00
Outdoor Enthusiasts     14,000         5%          12%        $90.00
Luxury Trend Followers 5,000         7%           11%        $70.00
University Students      24,000        5%           15%       $32.00
Answer:
From looking at the information provided about each segment, the segment which represents the greatest portion of the entire market at close to 36% is:
School Children.
Explanation:
a) Data and Calculations:
Demographic Data on Market Segments
Segment                         Market   Growth   Purchase   Average   Market
                                           Size        Rate     Behavior      Price       Size %
Urban Commuters       20,000         3%          23%        $45.00     20.4%
School Children            35,000         1%          20%        $24.00     35.7%
Outdoor Enthusiasts     14,000         5%          12%        $90.00      14.3%
Luxury Trend Followers 5,000         7%           11%        $70.00        5.1%
University Students      24,000        5%           15%       $32.00      24.5%
Total market size         98,000
b) Market Size in percentage is computed as a ratio of each market segment to the total market size.  Companies engage in market segmentation and sizing by dividing a target market into smaller, more defined categories that share similar characteristics such as demographics, interests, needs, or locations.  The purpose is to identify the different groups within the target market so that more tailored and valuable goods and services can be provided to meet the customers' sweet spots.