Statistics Week 3 Graded Assignments IIT Madras

1) The numbers 1, 5, 12,16 have frequencies X + 6, X + 2, X – 3 and Xrespectively. If their mean is 5.3, find the value of X. (Enter the value as next highest
integer)
Accepted Answers:
(Type: Numeric) 4

2) The mean and sample standard deviation of the dataset consisting of 7 observations is 19 and 8 respectively. Later it is noted that one observation 17 is
wrongly noted as 14. What is the mean of the original dataset? (Correct to 2 decimal place accuracy)
Accepted Answers:
(Type: Range) 19.13,19.73

3) The mean and sample standard deviation of the dataset consisting of 7 observations is 19 and 8 respectively. Later it is noted that one observation 17 is
wrongly noted as 14. What is the sample variance of the original dataset? (Correct to 2 decimal place accuracy)
Accepted Answers:
(Type: Range) 59.99,60.59

4) Let the data 32, 65, 98, 71, 56,40, 55, 60, 65 represent the retail prices in rupees of a certain commodity in 9 randomly selected shops in a particular city. What
will be the sample variance of the retail prices, if 3 rupees is added to all the retail prices. (Correct to 2 decimal place accurac
Accepted Answers:
(Type: Range) 354.64,355.24

5) Suppose, we have 6 observations such that 37, 30, 28, 37, 82,112.Calculate 10th, 50th and 100th percentiles?
28, 38.0, 112
29, 38.0, 112
28, 37.0, 112
28, 36.0, 112
Accepted Answers:
28, 37.0, 112

6) Suppose, we have 6 observations such that 45, 42, 28, 23, 95,119. Calculate the Inter Quartile Range (IQR) of the data.
96
67
95
68
Accepted Answers:
67

7) Suppose, we have 6 observations such that 45, 42, 28, 23, 95, 119. How many outliers are there?
0
4
1
3
2
Accepted Answers:
0

8) In a deck, there are cards numbered 1 to 44 such that the number of cards of a particular number in the deck is same as the number on the card. Which of 1 point
the following statement(s) is/are true about the mean and mode of the numbers on this deck of card?
Mode is not defined for this data.

Mean is 22.5.
Mode is 44.
Mode is 43.
Mean is 44.
Mean is 29.67.
Accepted Answers:
Mode is 44.
Mean is 29.67.

9) Figure 3.1 .G shows a stem and leaf plot of the ratings (out of 100) of an actor’s performance in different movies.

What is the Inter Quartile Range (IQR)? (Correct to 1 decimal point accuracy.)
Accepted Answers:
(Type: Range) 35.7,36.3

10) Figure 3.1.G shows a stem and leaf plot of the ratings (out of 100) of an actor’s performance in different movies.
What is the median rating, if 2 points are added to all of his ratings and then converted to 30 points. (Correct up to 2 decimal point accuracy.)
Accepted Answers:
(Type: Range) 24.3,24.90