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1. |
Create a
vector of 20 values from normal distribution with
mean = 20 and
sd = 3 |
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a) |
Obtain Mean
and Median of this data set |
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b) |
Using the function
'range' obtain the size of the biggest value and size of the smallest
value |
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2. |
Use
mtcars dataset of base R to perform following tasks |
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a) |
Display the dataset and create a
vector named mpg to store data about miles per gallon (mpg) of all the
cars. |
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b) |
Find the
standard deviation of above mentioned vector, i.e.
mpg,. |
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c) |
Using the
function 'quantile' obtain a vector including the following quantiles of
the data given in vector mpg:
i) 0%,
25%, 50%, 75%, 100%
ii) 5%, 35% and
95% |
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3. |
a) |
Create a vector of 100 values from a
binomial distribution with n = 9 and p = 0.3. |
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b) |
Use this vector to find frequency
distribution of values. |
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c |
Use
above mentioned vector to
Create a
histogram. |
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4. |
Generate 5
samples of sizes 5, 7, 6, 7 and 8 from normal populations with means 45,
40, 47, 43 and 38 respectively. While the standard deviations of these
distributions are 4, 6, 8, 7 and 9 respectively. Test the equality of
means. |
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5. |
A certain stimulus is to be
tested for its effect on blood pressure. Ten men have their blood
pressures measured before and after the stimulus. The results are shown
below:
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Man |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
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Before |
120 |
124 |
130 |
118 |
140 |
128 |
140 |
135 |
126 |
130 |
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After |
128 |
131 |
131 |
127 |
132 |
125 |
141 |
137 |
118 |
132 |
Is there reason to believe
that the stimulus would, on the average, raise the mean blood pressure by
5 points? |
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6. |
Given data
on the fuel consumption y of a car at various speeds x. Fuel consumption
is measured there in liters of gasoline per 100 kilometers driven, and
speed is measured in kilometers per hour.
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Speed |
10 |
20 |
30 |
40 |
50 |
60 |
80 |
100 |
120 |
130 |
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Fuel Used |
21 |
13 |
10 |
8 |
7 |
5.90 |
6.95 |
8.27 |
9.87 |
10.79 |
a) Make a scatter plot.
b) Obtain the least square line
c) Obtain the residuals
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7. |
Given data
on the fuel consumption y of a car at various speeds x. Fuel consumption
is measured there in liters of gasoline per 100 kilometers driven, and
speed is measured in kilometers per hour.
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Speed |
10 |
20 |
30 |
40 |
50 |
60 |
80 |
100 |
120 |
130 |
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Fuel Used |
21 |
13 |
10 |
8 |
7 |
5.90 |
6.95 |
8.27 |
9.87 |
10.79 |
a) Create a vaiable that is the
square of x. Obtain a regression line of y on x and x2.
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