| Date | May 2018 | Marks available | 2 | Reference code | 18M.1.sl.TZ1.6 |
| Level | SL only | Paper | 1 | Time zone | TZ1 |
| Command term | Calculate | Question number | 6 | Adapted from | N/A |
Question
In a high school, 160 students completed a questionnaire which asked for the number of people they are following on a social media website. The results were recorded in the following box-and-whisker diagram.
The following incomplete table shows the distribution of the responses from these 160 students.
Write down the median.
Complete the table.
Write down the mid-interval value for the 100 < x ≤ 150 group.
Using the table, calculate an estimate for the mean number of people being followed on the social media website by these 160 students.
Markscheme
180 (A1) (C1)
[1 mark]
36, 24 (A1)(A1) (C2)
Note: Award (A0)(A1) for two incorrect values that add up to 60.
[2 marks]
125 (accept 125.5) (A1)
\(\frac{{4 \times 25 + 36 \times 75 + 34 \times 125 + 46 \times 175 + 24 \times 225 + 16 \times 275}}{{160}}\) (M1)
Note: Award (M1) for correct substitution of their mid-interval values, multiplied by their frequencies, into mean formula.
=156 (155.625) (A1)(ft) (C3)
Note: Follow through from parts (b) and (c)(i).
[3 marks]
