# Selina solutions for Concise Mathematics Class 9 ICSE chapter 19 - Mean and Median (For Ungrouped Data Only) [Latest edition]

## Chapter 19: Mean and Median (For Ungrouped Data Only)

Exercise 19 (A)Exercise 19 (B)Exercise 19 (C)
Exercise 19 (A) [Pages 238 - 239]

### Selina solutions for Concise Mathematics Class 9 ICSE Chapter 19 Mean and Median (For Ungrouped Data Only) Exercise 19 (A) [Pages 238 - 239]

Exercise 19 (A) | Q 1 | Page 238

Find the mean of 43, 51, 50, 57 and 54.

Exercise 19 (A) | Q 2 | Page 238

Find the mean of the first six natural numbers.

Exercise 19 (A) | Q 3 | Page 238

Find the mean of the first ten odd natural numbers.

Exercise 19 (A) | Q 4 | Page 238

Find the mean of all factors of 10.

Exercise 19 (A) | Q 5 | Page 238

Find the mean of x + 3, x + 5, x + 7, x + 9 and x + 11.

Exercise 19 (A) | Q 6 | Page 238

If different values of variable x are 9.8, 5.4, 3.7, 1.7, 1.8, 2.6, 2.8, 8.6, 10.5 and 11.1;
find
(i) the mean  barx

(ii) the value of   sum (x_i - barx)

Exercise 19 (A) | Q 7.1 | Page 238

The mean of 15 observations is 32. Find the resulting mean, if the observation is: Increased by 3

Exercise 19 (A) | Q 7.2 | Page 238

The mean of 15 observations is 32. Find the resulting mean, if the observation is: Decreased by 7

Exercise 19 (A) | Q 7.3 | Page 239

The mean of 15 observations is 32. Find the resulting mean, if each observation is:  Multiplied by 2

Exercise 19 (A) | Q 7.4 | Page 239

The mean of 15 observations is 32. Find the resulting mean, if the observation is:  Divided by 0.5

Exercise 19 (A) | Q 7.5 | Page 239

The mean of 15 observations is 32. Find the resulting mean, if the observation is: Increased by 60%

Exercise 19 (A) | Q 7.6 | Page 239

The mean of 15 observations is 32. Find the resulting mean, if the observation is: Decreased by 20%

Exercise 19 (A) | Q 8 | Page 239

The mean of 5 numbers is 18. If one number is excluded, the mean of the remaining number becomes 16. Find the excluded number.

Exercise 19 (A) | Q 9 | Page 239

If the mean of observations x, x + 2, x + 4, x + 6 and x + 8 is 11,
find:
(i) The value of x;
(ii) The mean of first three observations.

Exercise 19 (A) | Q 10 | Page 239

The mean of 100 observations is 40. It is found that an observation 53 was misread as 83.
Find the correct mean.

Exercise 19 (A) | Q 11 | Page 239

The mean of 200 items was 50. Later on, it was discovered that two items were misread as 92 and 8 instead of 192 and 88.
Find the correct mean.

Exercise 19 (A) | Q 12 | Page 239

Find the mean of 75 numbers, if the mean of 45 of them is 18 and the mean of the remaining ones is 13.

Exercise 19 (A) | Q 13 | Page 239

The mean weight of 120 students of a school is 52.75 kg. If the mean weight of 50 of them is 51 kg,
find the mean weight of the remaining students.

Exercise 19 (A) | Q 14 | Page 239

The mean marks (out of 100) of boys and girls in an examination are 70 and 73 respectively. If the mean marks of all the students in that examination are 71,
find the ratio of the number of boys to the number of girls.

Exercise 19 (A) | Q 15 | Page 239

Find x if 9, x, 14, 18 x, x, 8, 10 and 4 have a mean of 11.

Exercise 19 (A) | Q 16 | Page 239

In a series of tests, A appeared for 8 tests. Each test was marked out of 30 and averages 25. However, while checking his files, A could only find 7 of the 8 tests. For these, he scored 29, 26, 18, 20, 27, 24 and 29.
Determine how many marks he scored for the eighth test.

Exercise 19 (B) [Page 241]

### Selina solutions for Concise Mathematics Class 9 ICSE Chapter 19 Mean and Median (For Ungrouped Data Only) Exercise 19 (B) [Page 241]

Exercise 19 (B) | Q 1.1 | Page 241

Find the median of: 25, 16, 26, 16, 32, 31, 19, 28 and 35

Exercise 19 (B) | Q 1.2 | Page 241

Find the median of:
241, 243, 347, 350, 327, 299, 261, 292, 271, 258 and 257

Exercise 19 (B) | Q 1.3 | Page 241

Find the median of:

63, 17, 50, 9, 25, 43, 21, 50, 14 and 34

Exercise 19 (B) | Q 1.4 | Page 241

Find the median of:

233, 173, 189, 208, 194, 204, 194, 185, 200 and 220.

Exercise 19 (B) | Q 2 | Page 241

The following data have been arranged in ascending order. If their median is 63, find the value of x.
34, 37, 53, 55, x, x + 2, 77, 83, 89 and 100.

Exercise 19 (B) | Q 3 | Page 241

In 10 numbers, arranged in increasing order, the 7th number is increased by 8, how much will the median be changed?

Exercise 19 (B) | Q 4 | Page 241

Out of 10 students, who appeared in a test, three secured less than 30 marks and 3 secured more than 75 marks. The marks secured by the remaining 4 students are 35, 48, 66 and 40. Find the median score of the whole group.

Exercise 19 (B) | Q 5 | Page 241

The median of observations 10, 11, 13, 17, x + 5, 20, 22, 24 and 53 (arranged in ascending order) is 18; find the value of x.

Exercise 19 (C) [Page 241]

### Selina solutions for Concise Mathematics Class 9 ICSE Chapter 19 Mean and Median (For Ungrouped Data Only) Exercise 19 (C) [Page 241]

Exercise 19 (C) | Q 1.1 | Page 241

Find the mean of 8, 12, 16, 22, 10 and 4. Find the resulting mean, if the observations, given above, be: multiplied by 3.

Exercise 19 (C) | Q 1.2 | Page 241

Find the mean of 8, 12, 16, 22, 10 and 4. Find the resulting mean, if the observations, given above, be: divided by 2.

Exercise 19 (C) | Q 1.3 | Page 241

Find the mean of 8, 12, 16, 22, 10 and 4. Find the resulting mean, if the observations, given above, be: multiplied by 3 and then divided by 2.

Exercise 19 (C) | Q 1.4 | Page 241

Find the mean of 8, 12, 16, 22, 10 and 4. Find the resulting mean, if each of the observations, given above, be:  increased by 25%

Exercise 19 (C) | Q 1.5 | Page 241

Find the mean of 8, 12, 16, 22, 10 and 4. Find the resulting mean, if each of the observations, given above, be:  decreased by 40%

Exercise 19 (C) | Q 2 | Page 241

The mean of 18, 24, 15, 2x + 1 and 12 is 21. Find the value of x.

Exercise 19 (C) | Q 3 | Page 241

The mean of 6 numbers is 42. If one number is excluded, the mean of the remaining number is 45. Find the excluded number.

Exercise 19 (C) | Q 4 | Page 241

The mean of 10 numbers is 24. If one number is included, the new mean is 25. Find the included number.

Exercise 19 (C) | Q 5 | Page 241

The following observations have been arranged in ascending order. If the median of the data is 78, find the value of x.
44, 47, 63, 65, x + 13, 87, 93, 99, 110.

Exercise 19 (C) | Q 6 | Page 241

The following observations have been arranged in ascending order. If the median of these observations is 58, find the value of x.
24, 27, 43, 48, x - 1, x + 3, 68, 73, 80, 90.

Exercise 19 (C) | Q 7 | Page 241

Find the mean of the following data: 30, 32, 24, 34, 26, 28, 30, 35, 33, 25
(i) Show that the sum of the deviations of all the given observations from the mean is zero.
(ii) Find the median of the given data.

Exercise 19 (C) | Q 8 | Page 241

Find the mean and median of the data: 35, 48, 92, 76, 64, 52, 51, 63 and 71.
If 51 is replaced by 66, what will be the new median?

Exercise 19 (C) | Q 9 | Page 241

The mean of x, x + 2, x + 4, x + 6 and x + 8 is 11, find the mean of the first three observations.

Exercise 19 (C) | Q 10 | Page 241

Find the mean and median of all the positive factors of 72.

Exercise 19 (C) | Q 11 | Page 241

The mean weight of 60 students in a class is 40 kg. The mean weight of boys is 50 kg while that of girls is 30 kg. Find the number of boys and girls in the class.

Exercise 19 (C) | Q 12 | Page 241

The average of n numbers x1, x2, x3 ….. xn is A. If x1 is replaced by  ( x+ α )x1, x2, is replaced by ( x+ α )x2 and so on.
Find the new average.

Exercise 19 (C) | Q 13 | Page 241

The heights (in cm) of the volleyball players from team A and team B were recorded as:
Team A: 180, 178, 176, 181, 190, 175, 187

Team B: 174, 175, 190, 179, 178, 185, 177

Which team had a greater average height?

Find the median of team A and team B.

## Chapter 19: Mean and Median (For Ungrouped Data Only)

Exercise 19 (A)Exercise 19 (B)Exercise 19 (C)

## Selina solutions for Concise Mathematics Class 9 ICSE chapter 19 - Mean and Median (For Ungrouped Data Only)

Selina solutions for Concise Mathematics Class 9 ICSE chapter 19 (Mean and Median (For Ungrouped Data Only)) include all questions with solution and detail explanation. This will clear students doubts about any question and improve application skills while preparing for board exams. The detailed, step-by-step solutions will help you understand the concepts better and clear your confusions, if any. Shaalaa.com has the CISCE Concise Mathematics Class 9 ICSE solutions in a manner that help students grasp basic concepts better and faster.

Further, we at Shaalaa.com provide such solutions so that students can prepare for written exams. Selina textbook solutions can be a core help for self-study and acts as a perfect self-help guidance for students.

Concepts covered in Concise Mathematics Class 9 ICSE chapter 19 Mean and Median (For Ungrouped Data Only) are Mean of Ungrouped Data, Properties of Mean, Concept of Median.

Using Selina Class 9 solutions Mean and Median (For Ungrouped Data Only) exercise by students are an easy way to prepare for the exams, as they involve solutions arranged chapter-wise also page wise. The questions involved in Selina Solutions are important questions that can be asked in the final exam. Maximum students of CISCE Class 9 prefer Selina Textbook Solutions to score more in exam.

Get the free view of chapter 19 Mean and Median (For Ungrouped Data Only) Class 9 extra questions for Concise Mathematics Class 9 ICSE and can use Shaalaa.com to keep it handy for your exam preparation