The IIT Madras BS Statistics for Data Science I (Stats 1) Qualifier paper sat on 10 Jul 2022, in the May 2022 term: 15 questions for 50 marks in 120 minutes. Every question is below with its answer. Take it as a timed mock test to be marked, or read it through first.
A news analyst collected the data on magnitude of earthquakes in Delhi for a year and concluded that the mean magnitude of earthquake in Delhi since 1900 BC is 3.7 on the Richter scale. Based on the given information, choose the correct option(s):
It is a time-series data.
It is a cross-sectional data.
The nature of study is descriptive.
The nature of study is inferential.
Correct answers
It is a time-series data.
The nature of study is inferential.
If the 75*^(th)* percentile of dataset 88, 70, x, 75, 76 is x, then what can be the possible value(s) of x?
76
75
80
None of these
Correct answers
76
80
Which of the following options is/are correct?
Language ability (i.e., Beginner, Intermediate, Proficient) has an ordinal scale of measurement.
Ranking of teams at the end of a cricket tournament has an interval scale of measurement.
City of birth has a nominal scale of measurement.
Temperature in Fahrenheit has a ratio scale of measurement.
Correct answers
Language ability (i.e., Beginner, Intermediate, Proficient) has an ordinal scale of measurement.
City of birth has a nominal scale of measurement.
Which of the following statements is/are incorrect about correlation coefficient?
The correlation coefficient is sensitive to outliers.
The correlation coefficient between two variables is always less than the covariance between them.
If the variables X and Y are independent, then the value of the correlation coefficient is zero.
The range of correlation coefficient is same as the range of point bi-serial correlation coefficient.
Correct answer
The correlation coefficient between two variables is always less than the covariance between them.
What is the relative frequency corresponding to the event Standup comedy? (Enter the answer correct to 2 decimal places)
Correct answer: 0.2 (accepted within ±0.03)
If the count of candidates participated in each event is increased by 1, then choose the correct option/s?
Mode of the data set will remain same.
Median of the data set will remain same.
Mode of the data set will change.
Mean of the data set will change.
Correct answer
Mode of the data set will remain same.
The data of second-hand cars is collected and shown in Table 1.3.Q. The car seller used this data to predict the price of his car in the market. Based on the given information, answer the given subquestions.
Which of the following statements is/are true?
Jazz 1.5 i-MMD is a case and Brand is a variable
Mileage is a case
Gas is a variable
Honda is a case
Number of Cylinders is a variable
Price is a variable
Correct answers
Jazz 1.5 i-MMD is a case and Brand is a variable
Number of Cylinders is a variable
Price is a variable
The data of second-hand cars is collected and shown in Table 1.3.Q. The car seller used this data to predict the price of his car in the market. Based on the given information, answer the given subquestions.
Which of the following statements is/are true?
Number of Cylinders is a quantitative and continuous variable.
Mileage is a quantitative and continuous variable.
Fuel Type is a qualitative variable.
Model Name is a quantitative variable.
Correct answers
Mileage is a quantitative and continuous variable.
Fuel Type is a qualitative variable.
The mean height of 6 members of group-A is 6 feet and the mean height of n members of group-B is 4 feet. If the sum of the heights of all members of both groups is same, then find the value of n
Correct answer: 9
If the population standard deviation of a dataset is 14 and the sample standard deviation of the same dataset is 15, find the number of observations in the dataset. (Enter the value as next highest integer)
Correct answer: 8
An analyst wants to know if the grades of a student is affected by the mode of delivery of education. He collects the data of students for the analysis and tabulated it in Table 1.1.Q.
Choose the correct option/s?
36% of the students got grade B in online mode.
50% of the students got either grade A or grade C in offline mode.
There is no association between the mode of delivery of education and grades of the student.
There is an association between the mode of delivery of education and grades of the student.
Correct answers
50% of the students got either grade A or grade C in offline mode.
There is an association between the mode of delivery of education and grades of the student.
Six employees are randomly selected from an office to check if their average working hours per week are affected by smoking. Their smoking behaviour and average working hours per week are recorded in Table 1.2.Q. Based on the given information, answer the given subquestions.
Calculate the absolute value of Point Bi-serial correlation coefficient between smoking behaviour and average working hours per week. (Enter the answer correct to 2 decimal places)
Correct answer: 0.09 (accepted within ±0.05)
Six employees are randomly selected from an office to check if their average working hours per week are affected by smoking. Their smoking behaviour and average working hours per week are recorded in Table 1.2.Q. Based on the given information, answer the given subquestions.
Are the average working hours per week of the employees strongly influenced by their smoking behaviour?
Yes, because the absolute value of Point Bi-serial coefficient is close to 1.
No, because the absolute value of Point Bi-serial coefficient is close to 1.
Yes, because the absolute value of Point Bi-serial coefficient is close to 0.
No, because the absolute value of Point Bi-serial coefficient is close to 0.
Correct answer
No, because the absolute value of Point Bi-serial coefficient is close to 0.
Table 1.4.Q. represents the stock of four different items in an electronic shop. If the distribution of TV is 25% and DVD players is 15%, of all the items, then based on the given information, answer the given subquestions.
What is the number of DVD players in the shop?
Correct answer: 300
Table 1.4.Q. represents the stock of four different items in an electronic shop. If the distribution of TV is 25% and DVD players is 15%, of all the items, then based on the given information, answer the given subquestions.
What is the number of Pen drives in the shop?
Correct answer: 900
