| Date | May 2018 | Marks available | 4 | Reference code | 18M.1.sl.TZ1.2 |
| Level | SL only | Paper | 1 | Time zone | TZ1 |
| Command term | Find | Question number | 2 | Adapted from | N/A |
Question
The following box-and-whisker plot shows the number of text messages sent by students in a school on a particular day.
Find the value of the interquartile range.
[2]
a.
One student sent k text messages, where k > 11 . Given that k is an outlier, find the least value of k.
[4]
b.
Markscheme
recognizing Q1 or Q3 (seen anywhere) (M1)
eg 4,11 , indicated on diagram
IQR = 7 A1 N2
[2 marks]
a.
recognizing the need to find 1.5 IQR (M1)
eg 1.5 × IQR, 1.5 × 7
valid approach to find k (M1)
eg 10.5 + 11, 1.5 × IQR + Q3
21.5 (A1)
k = 22 A1 N3
Note: If no working shown, award N2 for an answer of 21.5.
[4 marks]
b.
Examiners report
[N/A]
a.
[N/A]
b.
