Online Test — Statistics
10 Questions • 20 min • Chapter MCQ
20:00
Question 1 of 10
easy
A shopkeeper sold 20, 25, 30, 35 and 40 notebooks on five days. Mean sale per day is:
30
25
35
28
Explanation: Mean = 150/5 = 30.
Question 2 of 10
medium
Let a, b, c, d, e be the observations with mean m and standard deviation s. The standard deviation of the observations a+k, b+k, c+k, d+k, e+k is:
s + k
s/k
s
ks
Explanation: Adding a constant k to all observations simply translates the entire distribution without changing its spread. The standard deviation remains s.
Question 3 of 10
easy
The median of ₹120, ₹140, ₹150, ₹170, ₹200 is:
₹150
₹140
₹170
₹160
Explanation: Middle value is ₹150.
Question 4 of 10
easy
The median of 2, 5, 8, 11, 14, 17, 20, 23, 26 is:
14
11
17
13
Explanation: Middle (5th) value is 14.
Question 5 of 10
easy
The class mark of class interval 20–30 is:
25
20
30
15
Explanation: Class mark = (20 + 30)/2 = 25.
Question 6 of 10
medium
An ogive is mainly used to find:
Median
Mean
Mode
Range
Explanation: Median can be located using cumulative frequency curves.
Question 7 of 10
medium
Anil commutes to his office. His travel times in minutes for a week are 45, 50, 40, 55, 60. The variance of his commute time is:
45
50
55
60
Explanation: Mean = 250/5 = 50. Deviations squared: (45−50)²=25, 0, 100, 25, 100. Sum = 250. Variance = 250/5 = 50.
Question 8 of 10
easy
The algebraic sum of the deviations of a set of n values from their arithmetic mean is always:
0
1
n
Minimum
Explanation: By definition of the arithmetic mean, the positive deviations exactly balance the negative deviations, so their algebraic sum is 0: ∑(xᵢ − x̄) = 0.
Question 9 of 10
easy
In a class, marks obtained by five students are 40, 50, 60, 70 and 80. The mean marks are:
60
55
65
58
Explanation: Mean = (40+50+60+70+80)/5 = 300/5 = 60.
Question 10 of 10
easy
The standard deviation of the data 5, 5, 5, 5 is:
0
5
1
2
Explanation: Variance is 0, hence standard deviation is 0.