18M.1.SL.TZ1.T_2

pestleMathematicsAISLPaper 118M· sl-4-3-mean-median-mode-mean-of-grouped-data-standard-deviation-quartiles-iqrsource ↗

Each month the number of days of rain in Cardiff is recorded.
The following data was collected over a period of 10 months.

11 13 8 11 8 7 8 14 x 15

For these data the median number of days of rain per month is 10.

Find the value of x.

[2]

Find the standard deviation

[2]

b.i.

Find the interquartile range.

[2]

b.ii.

Markscheme / solution

* This question is from an exam for a previous syllabus, and may contain minor differences in marking or structure.

$\frac{{x + 11}}{2} = 10$ (M1)

Note: Award (M1) for correct substitution into median formula or for arranging all 9 values into ascending/descending order.

$\left( {x = } \right)\,\,9$ (A1) (C2)

[2 marks]

2.69 (2.69072…) (A2)(ft)

Note: Follow through from part (a).

[2 marks]

b.i.

13 − 8 (M1)
Note: Award (M1) for 13 and 8 seen.

= 5 (A1)(ft) (C4)
Note: Follow through from part (a).

[2 marks]

b.ii.

Examiners’ report

[N/A]

b.i.

[N/A]

b.ii.