Complete Study Pack for Engineering Entrances Objective Mathematics Vol 1>Chapter 20 - Statistics>Target Exercises>Q 7

MEDIUM

JEE Advanced

IMPORTANT

Earn 100

A frequency distribution has arithmetic mean $7.85$ , then the missing term is

Daily wages (in $₹$ ) $5$ $6$ $7$ $10$ $12$ $15$

Number of workers $10$ $f$ $13$ $8$ $5$ $4$

50% studentsanswered this correctly

Important Questions on Statistics

EASY

JEE Advanced

IMPORTANT

Complete Study Pack for Engineering Entrances Objective Mathematics Vol 1>Chapter 20 - Statistics>Target Exercises>Q 8

The mean of

20

observations is

15

. On checking, it was found that the two observations were wrongly copied as

3

and

6

. The correct values are

8

and

4

. Then, the correct mean will be given by

MEDIUM

JEE Advanced

IMPORTANT

Complete Study Pack for Engineering Entrances Objective Mathematics Vol 1>Chapter 20 - Statistics>Target Exercises>Q 9

The mean of

100

items is

49

. It was later discovered that three items taken as

40, 20, 50

were actually

60, 70, 80

, respectively. The correct mean is

MEDIUM

JEE Advanced

IMPORTANT

Complete Study Pack for Engineering Entrances Objective Mathematics Vol 1>Chapter 20 - Statistics>Target Exercises>Q 10

The average weight of a class of

14

students is

42 kg

. If the teacher is included then average weight increases by

400 g

, then weight of the teacher is

MEDIUM

JEE Advanced

IMPORTANT

Complete Study Pack for Engineering Entrances Objective Mathematics Vol 1>Chapter 20 - Statistics>Target Exercises>Q 11

The mean of the series

1, 2, 4, 8, \dots, 2^{n}

is

MEDIUM

JEE Advanced

IMPORTANT

Complete Study Pack for Engineering Entrances Objective Mathematics Vol 1>Chapter 20 - Statistics>Target Exercises>Q 12

The algebraic sum of the deviations of

20

observations measured from

30

is

2

. The mean of observations is

MEDIUM

JEE Advanced

IMPORTANT

Complete Study Pack for Engineering Entrances Objective Mathematics Vol 1>Chapter 20 - Statistics>Target Exercises>Q 13

A class of

30

boys and

15

girls is given a test in mathematics. The average marks obtained by boys is

15

and by girls is

6

. The average of whole class is

MEDIUM

JEE Advanced

IMPORTANT

Complete Study Pack for Engineering Entrances Objective Mathematics Vol 1>Chapter 20 - Statistics>Target Exercises>Q 14

If the arithmetic mean of

9

observations is

100

and that of

6

is

80

. Then, the combined mean of all the

15

observations will be

MEDIUM

JEE Advanced

IMPORTANT

Complete Study Pack for Engineering Entrances Objective Mathematics Vol 1>Chapter 20 - Statistics>Target Exercises>Q 15

Combined mean of two series

x_{1}

and

x_{2}

, when

Σ x_{1} = 210, Σ x_{2} = 150, n_{1} = 50, n_{2} = 100

is