CBSE Class 10 Mathematics Statistics Assignment Set B

Question. For the following grouped frequency distribution

Consider the following.
(I) Lower limit of model class is 12
(II) Frequency of the class preceding the model class = 10
(III) Mode = 14.6
(IV) Width of the model class is 4
Which of the following is correct?
(a) I and II
(b) II and III
(c) I, II and III
(d) All of these

Answer: C

Question. The marks in science of 80 students of class X are given below. Find the mode of these marks obtained by the students in science.

(a) 53.18
(b) 53.25
(c) 52.25
(d) 53

Answer: A

Question. There are three sections A, B and C in class X with 25, 40 and 35 students respectively. The average marks obtained by section A, B and C are 70%, 65% and 50% respectively. Find the average marks of entire class X.
(a) 59%
(b) 56%
(c) 63%
(d) 61%

Answer: D

Question. The mean weight of a class of 35 students is 45kg. If the weight of a teacher be included, the mean weight increases by 500 grams. Find the weight of the teacher.
(a) 63 kg
(b) 61 kg
(c) 64 kg
(d) 70 kg

Answer: A

Question. In the following distribution

the number of families having income range (in ₹) 16000 – 19000 is
(a) 15
(b) 16
(c) 17
(d) 19

Answer: D

Question. Find the mean of the following frequency distribution.

(a) 25. 3
(b) 25.2
(c) 24
(d) 25.5

Answer: B

Question. Calculate the mean of the following frequency distribution

(a) 195.5
(b) 198.8
(c) 196.8
(d) 195

Answer: C

Question. If the mean of first ‘n’ odd natural numbers is ‘n’ itself, what is the value of ‘n’?
(a) 2
(b) 3
(c) 1
(d) Any natural number

Answer: D

Question. What is the arithmetic mean of 20 fours, 40 fives, 30 sixes and 10 tens?
(a) 50
(b) 25
(c) 5.6
(d) 33

Answer: C

Question. If the mean of the numbers 27 + x, 31 + x, 89 + x, 107 + x, 156 + x is 82, then the mean of 130 + x, 126 + x, 68 + x, 50 + x, 1 + x is
(a) 75
(b) 157
(c) 82
(d) 80

Answer: A

Question. If the class-intervals are 10 – 19, 20 – 29, 30 – 39, .............., then the upper limit of the first class-interval is
(a) 19.5
(b) 19
(c) 20
(d) None of these

Answer: A

Question. The numbers 3, 5, 7 and 9 have their respective frequencies x – 2, x + 2 , x – 3 and x + 3. If the arithmetic mean is 6.5, then the value of x is
(a) 3
(b) 4
(c) 5
(d) 6

Answer: C

Question. The median of a set of 9 distinct observations is 20.5. If each of the largest 4 observation of the set is increased by 2, then the median of the new set
(a) is increased by 2
(b) is decreased by 2
(c) is two times the original median
(d) remains the same as that of the original set

Answer: D

Question. A set of numbers consists of three 4’s, five 5’s, six 6’s, eight 8’s and seven 10’s. The mode of this set of numbers is
(a) 6
(b) 7
(c) 8
(d) 10

Answer: C

Question. The mean of a set of 20 observation is 19.3. The mean is reduced by 0.5 when a new observation is added to the set. The new observation is
(a) 19.8
(b) 8.8
(c) 9.5
(d) 30.8

Answer: B

Question. In a frequency distribution, the mid value of a class is 10 and the width of the class is 6. The lower limit of the class is
(a) 6
(b) 7
(c) 8
(d) 12

Answer: B

Question. If the mean of the observations x, x + 3, x + 5, x + 7 and x + 10 is 9, then the mean of the last three observations is
(a) 10(1/3)
(b) 10(2/3)
(c) 11(1/3)
(d) 11(2/3)

Answer: C

Question. The mean of fifteen different natural numbers is 13. The maximum value for the second largest of these numbers is
(a) 46
(b) 51
(c) 52
(d) 53

Answer: B

Question. For the data (2, 9, x + 6, 2x + 3, 5, 10, 5) if mean is 7, then mode is
(a) 3
(b) 5
(c) 9
(d) 10

Answer: C

Question. The mean of three positive numbers is 10 more than the mallest of the numbers and 15 less than the largest of the three. If the median of the three numbers is 5, then the mean of squares of the numbers is
(a) 108(2/3)
(b) 116(2/3)
(c) 208(1/3)
(d) 216(2/3)

Answer: D

Question. Positive integers from 1 to 21 are arranged in 3 groups of 7 integers each, in some particular order. Then the highest possible mean of the medians of these 3 groups is ______
(a) 16
(b) 12.5
(c) 11
(d) 14

Answer: D

Question. The mean of 5 observation is 15. If the mean of first three observations is 14 and last three observations is 17, then the third observation is :
(a) 18
(b) 19
(c) 17
(d) 20

Answer: A

Question. The mean of a group of eleven consecutive natural numbers is m. What will be the percentage change in the mean when next six consecutive natural numbers are included in the group ?
(a) m%
(b) (3/m) %
(c) (300/m) %
(d) (300/m)%

Answer: D

Question. A 100 mark examination was administered to a class of 50 students. Despite only integer marks being given, the average score of the class was 47.5. Then, the maximum number of students who could get marks more than the class average is
(a) 25
(b) 35
(c) 45
(d) 49

Answer: D

Question. Let x₁, x₂ , ..., x₁₁ be 11 distinct positive integers. If we replace the largest of these integers by the median of the other 10 integers, then
(a) the median remains the same
(b) the mean increases
(c) the median decreases
(d) the mean remains the same

Answer: C

Question. The mean of 15 observations written in some order is 50. If the mean of first eight observations and last eight observations are 48 and 53 respectively, then the eighth observation is
(a) 35
(b) 80
(c) 72
(d) 58

Answer: D

Question. The upper limit of modal class is
(a) 15
(b) 25
(c) 35
(d) 45

Answer: C

Question. The mean of the given data is
(a) 26.2
(b) 32.4
(c) 33.5
(d) 35.4

Answer: D

Question. The mode of the given data is
(a) 41.4
(b) 48.2
(c) 55.3
(d) 64.6

Answer: A

Question. The median of the given data is
(a) 32.7
(b) 40.2
(c) 42.3
(d) 48.6

Answer: B

Fill in the Blanks

DIRECTIONS : Complete the following statements with an appropriate word / term to be filled in the blank space(s).

Question. Median divides the total frequency into .......... equal parts.
Answer: two

Question. The mid-value of 20-30 is .................
Answer: 25

Question. The sum of 12 observations is 600, then their mean is .........
Answer: 50

Question. In the class interval 35-46, the lower limit is ....... and upper limit is .............
Answer: 35, 46

Question. A class interval of a data has 15 as the lower limit and 25 as the size, then the class mark is .............
Answer: 27.5

Question. The algebraic sum of the deviations from arithmetic mean is always ...............
Answer: zero

Question. The class mark of a class is 25 and if the upper limit of that class is 40, then its lower limit is ...................
Answer: 10

Question. 0–10, 10–20, 20–30 ............ so on are the classes, the lower boundary of the class 20–30 is ...............
Answer: 20

Question. The mid-point of a class interval is called its ................
Answer: class-mark

Question. The ................. is the most frequently occurring observation.
Answer: mode

Question. 3 median = mode + ............. mean
Answer: 2

Question. To find the mode of a grouped data, the size of the classes is ..................
Answer: uniform

Question. On an ogive, point A (say), whose Y- co-ordinate is n/2 (half of the total observation), has its X-coordinate equal to .................. of the data.
Answer: Median

Question. Facts or figures, collected with a definite purpose, are called ..................
Answer: data

Question. Value of the middle-most observation (s) is called ............
Answer: median

Question. Two ogives, for the same data intersect at the point P. Then, Y-coordinate of P represents .................. .
Answer: cumulative frequency of the median class.

True / False

DIRECTIONS : Read the following statements and write your answer as true or false.

Question. Class mark = Upper class limit + Lower class limit/2
Answer: True

Question. The median of grouped data with unequal class sizes cannot be calculated.
Answer: False

Question. Median of 15, 28, 72, 56, 44, 32, 31, 43 and 51 is 43.
Answer: True

Question. Mode of 2, 3, 4, 5, 0, 1, 3, 3, 4, 3 is 3.
Answer: True

Question. The modal value is the value of the variate which divides the total frequency into two equal parts.
Answer: False

Question. The mean of x, y, z is y, then x + z = 2y
Answer: True

Question. 2(Median – Mean) = Mode – Mean.
Answer: False

Question. Mean may or may not be the appropriate measure of central tendency.
Answer: True

Question. If 16 observations are arranged in ascending order, then median is (8th observation + 9th observation)/2
Answer: True

Question. Mean of 41, 39, 48, 52, 46, 62, 54, 40, 96, 52, 98, 49, 42, 52, 60 is 55.4
Answer: True

Level-1

Please refer to attached file for CBSE Class 10 Mathematics Statistics Assignment Set B