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 travel times for two sampled bus routes, recorded to the nearest minute. Each leaf is one recorded observation. The group on the left is Route A; the group on the right is Route B

Route ARoute B

7 531 5 7 9

7 5 4 3 1 043 5 7 9

153 9

Key: Route A (left): 5 | 3 means 35 min
Route B (right): 2 | 7 means 27 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 Route A Median for Route A (min) Count for Route B Median for Route B (min)

(b)1 mark

Which comparison is supported by the recorded samples?

The sample with more observations must have a higher median

The sample median for Route B is higher

Every observation equals its sample median

The sample medians are equal