Statistics: Spread, Ogives & Box Plots (Grade 11) — Worksheet & Memo

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Grade 11 · Statistics

Statistics: Spread, Ogives & Box Plots (Grade 11)

WORKSHEET

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/ 31

Answer all questions. Show all your working — marks are awarded for method as well as the final answer.

1
The mean of 64, 71, 58, 67 and x is 66. Solve for x.
(3)
2
For the box-and-whisker diagram below, write down the five-number summary.
(3)
3
Calculate the interquartile range from the diagram below.
(2)
4
Calculate the mean of 12 ; 15 ; 18 ; 18 ; 21 ; 24 ; 27 ; 30 ; 33.
(2)
5
Calculate the standard deviation of 12 ; 15 ; 18 ; 18 ; 21 ; 24 ; 27 ; 30 ; 33.
(3)
6
How many data values lie within one standard deviation of the mean for the data above?
(2)
7
Use the ogive below to estimate the median mark.
(2)
8
Use the ogive below to write down the total number of learners.
(1)
9
Determine the outlier boundaries for the box plot below.
(3)
10
Estimate the mean of: 0–10 (f = 4), 10–20 (f = 9), 20–30 (f = 12), 30–40 (f = 5).
(4)
11
Why can the mean of grouped data only be ESTIMATED?
(2)
12
At which point of each interval must a frequency polygon be plotted, and why?
(2)
13
State ONE difference between a frequency polygon and an ogive.
(2)

TOTAL: 31 marks