Page 281 - Data Science class 11
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B. Fill in the blanks.
1. ______________________ is an R package used for statistical computing and data representation using Data Visualization.
2. R language supports two ways to plot a bar plot which is ______________________ and ______________________.
3. A ______________________ is a graphical representation that organises a group of data points into user-specified ranges.
4. The ______________________ attribute is used to remove the missing values from the input vector.
5. ______________________ are a measure of how well distributed the data is in a data set.
C. State whether these statements are true or false.
1. The mean is the value that has the highest number of occurrences in a set of data. _____________
2. The function that is used to plot a boxplot is boxplot (). _____________
3. Scatter plots show many points plotted in the Cartesian plane. _____________
4. Line charts uses boxes to represent change over time. _____________
5. The parameter/attribute radius is applied for Pie charts. _____________
Standard Questions (Section B)
A. Short answer type questions:
1. Write a note on Median and how is it calculated in R.
Ans. The Median is a measure of Central Tendency that gives the value of the middle-most observation in the data. The
function that is used to calculate median is median (). The syntax is: median (x, na.rm=FALSE).
2. Write a note on Boxplot.
Ans. A boxplot is a graphical technique for summarising a set of data on an interval scale. It is used in descriptive data
analysis. The function boxplot () of R programming language is used to plot a boxplot. The syntax is: boxplot (x, data,
notch, varwidth, names, main).
x: is a vector or a formula.
data: is the data frame
notch: is a logical value, set as TRUE to draw a notch.
varwidth: is a logical value, set as TRUE to draw width of the box proportionate to the sample size.
names: are the group labels which will be printed under each boxplot.
main: is used to give a title to the graph.
B. Long answer type questions:
1. What is Histogram? Give an example to demonstrate the plotting of a histogram.
Ans. A histogram is a graphical representation that organises a group of data points into user-specified ranges. It is similar to
a bar chart, but the difference is that it groups the values into continuous ranges. Each bar in the histogram represents
the height of the number of values present in that range. It is used to summarise discrete or continuous data that are
measured on an interval scale. It is used to show the distribution of variables, while bar charts are used to compare
variables. It is simple and versatile.
The function hist() is used to create histogram. The syntax is hist(v,main,xlab,xlim,ylim,breaks,col,border)
Coding for Data Science Visualisation using R-Studio 279

