1. Indicate which of the following would show a positive correlation, which would show a negative correlation and which would show no correlation.
   1. the height of a flying kite and the speed of the wind
   2. the time spent practicing shooting a basketball and the number of misses in 10 shots
   3. the length of a piece of string and the colour of the string

Jamaal decides to select a sample of the population at his school to survey in order to determine the most watched show on TV. He divides the school population into males and females, and into grades.

He then sends 5 male survey forms and 5 female survey forms to each homeroom in the school to collect his information.

1. What type of sampling technique is Jamaal using?
2. Identify any bias that may exist in his sampling technique?
3. Suggest possible ways of reducing this bias.