A student records the number of plants in eight randomly positioned quadrats.
The counts are 0,0,1,1,2,2,2,80, 0, 1, 1, 2, 2, 2, 80,0,1,1,2,2,2,8 .
The student removes both zero counts before calculating a mean to estimate the population of the whole field.
Which statement correctly describes the effect of this decision?
The mean changes from $1.5{\char"24}1.5$1.5 to $2.0{\char"24}2.0$2.0 , making the population estimate too high.
The mean changes from $2.0{\char"24}2.0$2.0 to $1.5{\char"24}1.5$1.5 , making the population estimate too low.
The mean changes from $2.67{\char"24}2.67$2.67 to $2.0{\char"24}2.0$2.0 , making the population estimate too low.
The mean changes from $2.0{\char"24}2.0$2.0 to $2.67{\char"24}2.67$2.67 , making the population estimate too high.
40 exam-style questions on AQA GCSE Biology 7.2 Organisation of an ecosystem, covering 7.2.1 Levels of organisation, 7.2.2 How materials are cycled, 7.2.3 Decomposition, and 7.2.4 Impact of environmental change (HT only). Each one has a worked solution and a mark scheme showing where the marks go.