Pregunta 33

A pupil orders the five seedling heights 4, 4, 4, 9 and 10 centimetres and gives the median as 9 centimetres. Which statement identifies the mistake in this median calculation?

The heights were never put in order, so no position can be read from them.
Each repeated height holds a position of its own, so the central position holds 4 centimetres.Respuesta correcta
The median of five values is the mean of the two central heights, which comes to 6.5 centimetres.
The median should be 6.2 centimetres, because that is the mean of the five recorded heights.

Explicación

The five heights are already sorted, so the median is whatever stands in the central one of the five positions, and because 4 centimetres occurs three times it fills the first three of those positions. Giving 9 centimetres treats the three equal heights as a single entry, which shortens the list to three items and moves the centre to the wrong place.

Explicación

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