JEE Questions for Maths Statistics Quiz 1

The mean deviation from the mean of the set of observations -1, 0, 4 is

0%
3
0%
1
0%
-2
0%
2

0%
0%
2)
0%
0%
None of these

The mean of the numbers a, b, 8, 5, 10, is 6 and the variance is 6.80. Then, which one of the following gives possible values of a and b ?

0%
a = 3, b = 4
0%
a = 0, b = 7
0%
a = 5, b = 2
0%
a = 1, b = 6

The AM of 9 terms is 15. If one more term is added to this series, then AM becomes 16. The value of the added term is

0%
30
0%
27
0%
25
0%
23
0%
20

In a moderately asymmetrical distribution, if the mean and median are 36 and 34 respectively, then find out the value of empirical mode.

0%
30
0%
32
0%
42
0%
22

The mean age of a combined group of men and women is 25 yr. If the mean age of the group of mean is 26 and that of the group of women is 21, then the percentage of men and women in the group is

0%
46, 60
0%
80, 20
0%
20, 80
0%
60, 40

The values of mean, median and mode coincide, then the distribution is

0%
positive skewness
0%
symmetric distribution
0%
negative skewness
0%
All of these

In a class of 100 students, there are 70 boys, whose average marks in a subject are 75. If the average marks of the complete class is 72, then what is the average marks of the girls ?

0%
73
0%
65
0%
68
0%
74

0%
9
0%
4
0%
3
0%
2
0%
1

0%
18
0%
12
0%
15
0%
16

The mean of four observations is 3. If the sum of the squares of theee observations is 48, then their standard deviation is

0%
√7
0%
√2
0%
√3
0%
√5

The sum of the deviations of the variates from the arithmetic mean is always

0%
+1
0%
0
0%
-1
0%
real number

All the students of a class performed poorly in mathematics. The teacher decided to give grace marks of 10 to each of the students. Which of the following statistical measures will not change even after the grace marks were given?

0%
Mean
0%
Median
0%
MOde
0%
Variance

A scientist is weighing each of 30 fishes. Their mean weight worked out is 30 g and a standard deviation is 2 g. Later, it was found that the measuring scale was misaligned and always under reported every fish weight by 2 g. Find the correct mean and standard deviation (in gram) of fishes.

0%
28, 4
0%
32, 2
0%
32, 4
0%
28, 2

0%
100
0%
10
0%
15
0%
50

If the standard deviation of 3, 8, 6, 10, 12, 9, 11, 10, 12, 7 is 2.71, then the standard deviation of 30, 80, 60, 100, 120, 90, 110, 100, 120, 70 is

0%
2.71
0%
27.1
0%
(2.71)√10
0%
(2.71)√2
0%
0.271

Mean deviation of 6, 8, 12, 15, 10, 9 through mean is

0%
10
0%
2.33
0%
2.5
0%
None of these

If the value observed are 1, 2, 3..., n each with frequency l and m is even, then the mean deviation from mean equals to

0%
n
0%
n/2
0%
n/4
0%
None of these

0%
80
0%
25
0%
20
0%
16
0%
4

If the coefficient of variation is 45% and the mean is 12, then its standard deviation is

0%
5.2
0%
5.3
0%
5.4
0%
None of these

0%
0%
5
0%
√5
0%
3/2

0%
11
0%
12
0%
23
0%
22

0%
0.89
0%
0.76
0%
0.91
0%
0.98

Two numbers within the brackets denote the ranks of 10 students of a class in two subjects (1, 10), (2, 9), (3, 8), (4, 7), (5, 6), (6, 5), (7, 4), (8, 3), (9, 2), (10, 1), then rank correlation coefficient is

0%
0
0%
-1
0%
1
0%
0.5

If the variance of x is 9 and regression equations are 4x - 5y + 33 = 0 and 20x - 9y - 10 = 0, then the coefficient of correlation between x and y and the variance of y respectively are