A dataset is represented by the dot plot drawn below.
Determine the standard deviation of the dataset, giving your answer correct to two decimal places. (2 marks)
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A dataset is represented by the dot plot drawn below.
Determine the standard deviation of the dataset, giving your answer correct to two decimal places. (2 marks)
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\(\text{Std Dev}\ = 1.25\)
\(\text{Dataset values:}\ 0, 1, 1, 2, 2, 3, 4 \)
\(\text{By calculator (using Statistics mode):}\)
\(\text{Std Dev}\ = 1.245… = 1.25\ \text{(2 d.p.)} \)
Isa Guha recorded the number of sixes hit in the first nine games of the Women's Big Bash Cricket League over two seasons.
The results are recorded in the two dot plots below.
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i. \(\text{Std Dev}\ = 1.9\ \text{(1 d.p.)} \)
ii. \(\text{By inspection, season 1 has a slightly higher range}\)
\(\text{(5 vs 4) and its data points can be seen to be much}\)
\(\text{wider spread about the expected mean value.}\)
\(\text{Season 1 will therefore have a higher standard deviation.}\)
i. \(\text{Season 1 dataset:}\ 6, 6, 7, 8, 10, 10, 10, 11, 11\)
\(\text{By calculator (using Statistics mode):}\)
\(\text{Std Dev}\ = 1.930… = 1.9\ \text{(1 d.p.)} \)
ii. \(\text{By inspection, season 1 has a slightly higher range}\)
\(\text{(5 vs 4) and its data points can be seen to be much}\)
\(\text{wider spread about the expected mean value.}\)
\(\text{Season 1 will therefore have a higher standard deviation.}\)
Two data sets are represented in the dot plot diagrams below.
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i. \(\text{Std Dev}\ = 1.79… = 1.8\ \text{(1 d.p.)} \)
ii. \(\text{By inspection, Data Set A has a smaller range and a tighter}\)
\(\text{spread against its expected mean value.}\)
\(\text{Data Set B will therefore have a higher standard deviation.}\)
i. \(\text{Data points:}\ 4, 4, 5, 5, 6, 6, 7, 8, 9, 9\)
\(\text{By calculator (using Statistics mode):} \)
\(\text{Std Dev}\ = 1.79... = 1.8\ \text{(1 d.p.)} \)
ii. \(\text{By inspection, Data Set A has a smaller range and a tighter}\)
\(\text{spread against its expected mean value.}\)
\(\text{Data Set B will therefore have a higher standard deviation.}\)
All the students in a class of 30 did a test.
The marks, out of 10, are shown in the dot plot.
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i. \(\text{30 data points}\)
\(\text{Median}\ = \dfrac{\text{15th + 16th}}{2} = \dfrac{4+8}{2} = 6\)
ii. \(\text{Lower limit}\ = 5.4-4.22 = 1.18\)
\(\text{Upper limit} = 5.4 + 4.22 = 9.62\)
\(\text{% between}\) | \(= \dfrac{13}{30} \times 100\) | |
\(= 43.33… \%\) | ||
\(=43\%\ \ \text{(nearest %)}\) |