

SAT Mathematics - Statistics
Exam Duration: 45 Mins Total Questions : 30
The formula for finding mode in a grouped frequency distribution is \(1+\left( \frac { { f }_{ 1 }-{ f }_{ 0 } }{ 2{ f }_{ 1 }-{ f }_{ 0 }-{ f }_{ 2 } } \right) \times h\) What does f1 represent here?
- (a)
frequency of the modal class
- (b)
frequency of the class preceding the modal class
- (c)
frequency of the class succeeding the modal class
- (d)
frequency of the last class
The formula for finding out the median in a grouped frequency distribution is \(1+\frac { \left( \frac { n }{ 2 } -f \right) }{ f } \times h\) What does f represent here?
- (a)
frequency of the class preceding the median class
- (b)
cumulative frequency of the class preceding the median class
- (c)
frequency of the class succeeding the median class
- (d)
cumulative frequency of the class succeeding the median class
The weight of 12 men are given as 75, 73, 73, 72, 72, 72, 70, 70, 68, 68, 68, 68, kg. Find the mean weight?
- (a)
70.75 kg
- (b)
70.75 g
- (c)
71.75 kg
- (d)
none of these
Determine the mean of the following
Group | 10-16 | 16-22 | 22-28 | 28-34 | 34-40 |
Frequency | 1 | 10 | 5 | 3 | 6 |
- (a)
24.72
- (b)
25.77
- (c)
25.72
- (d)
none of these
Following is the distribution of earnings of 200 workers in a flour mill:
Monthly wages (in rupees) |
80-100 | 100-120 | 120-140 | 140-160 | 160-180 |
No.of workers | 20 | 30 | 20 | 40 | 90 |
Estimate the average earnings of the workers
- (a)
115
- (b)
125
- (c)
135
- (d)
145
The average weight of A, B, Cis 45 kg. If the average weight of A and B be 40 kg and that of B and C be 43 kg, find the weight of B?
- (a)
21 kg
- (b)
20 kg
- (c)
38 kg
- (d)
31 kg
Which of the following relations true?
- (a)
AM=HM
- (b)
GM=AM=HM
- (c)
AM<HM
- (d)
AM≥GM≥HM
Calculate the median for the following?
Marks Obtained | No.of Students |
Below 10 | 6 |
Below 20 | 15 |
Below 30 | 29 |
Below 40 | 41 |
Below 50 | 60 |
Below 60 | 70 |
- (a)
35
- (b)
45
- (c)
55
- (d)
none of these
If the AM as well as GM of two positive numbers is 4, what is their HM?
- (a)
2
- (b)
4
- (c)
8
- (d)
none of these
The arithmetic mean of the scores of a group of students in a test was 52. The brightest 20% of them secured a mean score of 80 and the dullest 25% a mean score of 31. The mean score of remaining 55% is
- (a)
45
- (b)
50
- (c)
51.4 approx
- (d)
54.6 approx
Three years ago, the average age of A and B was 18years with C joining them, the average age becomes 22 years. How old is C now?
- (a)
24 years
- (b)
27 years
- (c)
28 years
- (d)
30 years
After replacing an old member by a new member, it was found that the average age of five members of a club is the same as it was B years ago. What is the difference between the ages of the replaced and the new member?
- (a)
2 years
- (b)
4 years
- (c)
8 years
- (d)
15 years
Which class interval has minimum frequency in the following group?
- (a)
20-30
- (b)
40-50
- (c)
50-60
- (d)
0-10
Which is the better measure of central tendency when individual observation are not important?
- (a)
Mode
- (b)
Median
- (c)
Mean
- (d)
none of these
Find the class marks of classes 10-25 and 33-55
- (a)
10,35
- (b)
25,55
- (c)
15,20
- (d)
17.5,45
The item value which occurs most frequently is called
- (a)
Mean
- (b)
Median
- (c)
Mode
- (d)
none of these
The class, whose cumulative frequency is greater than (and nearest to) n/2 is called
- (a)
Average class
- (b)
Median class
- (c)
Modal class
- (d)
Mean class
The algebraic sum of all the deviations of all the observations from their mean is always
- (a)
0
- (b)
+ve
- (c)
-ve
- (d)
equal to the number of observations
If mean = (3 median-mode) /k, then k=
- (a)
1
- (b)
1/2
- (c)
2
- (d)
none of these
Which of the following formulae is true for finding mean?
- (a)
\(\bar { x } =\frac { \sum _{ i=1 }^{ n }{ { x }_{ i } } }{ n } \)
- (b)
\(\bar { x } =\sum _{ i=1 }^{ n }{ \sum { x_{ i }^{ 2 } } } \)
- (c)
\(\bar { x } =\frac { \sum _{ i=1 }^{ n }{ { x }_{ i } } }{ { n }^{ 2 } } \)
- (d)
\(\bar { x } =\frac { \sum _{ i=1 }^{ n }{ { x }_{ i }^{ 2 } } }{ { n }^{ 2 } } \).
Find the sum of the deviations of the variate values 3, 4, 6, 7, 8, 14 from their mean.
- (a)
0
- (b)
3
- (c)
4
- (d)
1
The mean of n observations x1, x2, x3, ....., xn is \(\bar { x } \) . If each observation is divided by p, then the mean of the new observation is
- (a)
\(\frac { \bar { x } }{ p } \)
- (b)
\(p\bar { x } \)
- (c)
\(\bar { x } \)
- (d)
\(p+\bar { x } \)
If the mode of the following distribution is 2.8, then find the values of x.
2.5, 2.5, 2.1, 2.7, 2.8, 2.5, x, 2.8, 2.7
- (a)
2.8
- (b)
2.7
- (c)
2.5
- (d)
2.1
The position average is
- (a)
Mean
- (b)
Mode
- (c)
Median
- (d)
Geometric Mean
The modal value of a series is
- (a)
middle most value
- (b)
value whose frequency is maximum
- (c)
value whose frequency is minimum
- (d)
limiting value
The algebraic sum of all the deviations of all the observations from their mean is always
- (a)
0
- (b)
+ve
- (c)
-ve
- (d)
equal to number of observation
The mean of first n natural number is
- (a)
\(\frac { n+1 }{ 2 } \).
- (b)
\(\frac { n(n+1) }{ 2 } \)
- (c)
\(\frac { n(n-1) }{ 2 } \)
- (d)
n2
The width of the class interval 40-50 is
- (a)
40
- (b)
50
- (c)
45
- (d)
10
The median and mode of a distribution are 7.5 and 6.5 respectively. Find the mean
- (a)
4
- (b)
8
- (c)
6.5
- (d)
7.5
Find the average of all prime numbers between 30 and 50
- (a)
37.8
- (b)
39.8
- (c)
29.8
- (d)
none of these