1 of 8 0-day streak

Compare a numerical variable across groups

Question 1 of 8

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The back-to-back stem plot compares waiting times in two sampled queues, recorded to the nearest tenth of a minute. Each leaf is one recorded observation. The group on the left is Queue A; the group on the right is Queue B

Queue AQueue B

8 6 236 8

8 6 4 041 2 4 5 6 8

4 052

Key: Queue A (left): 8 | 2 means 2.8 min
Queue B (right): 3 | 6 means 3.6 min

(a)4 marks

Count the observations and find each sample median. Read the left leaves outwards from the stem; work with the recorded values, not the leaf digits alone

Count for Queue A Median for Queue A (min) Count for Queue B Median for Queue B (min)

(b)1 mark

Which comparison is supported by the recorded samples?

The sample median for Queue B is higher

The sample medians are equal

Every observation equals its sample median

The sample with more observations must have a higher median