# NCERT Mathematics Class 9 Exemplar Ch 14 Statistics and Probability Part 4

19. There are 50 numbers. Each number is subtracted from 53 and the mean of the numbers so obtained is found to be. The mean of the given numbers is:

(A)

(B)

(C)

(D)

20. The mean of 25 observations is 36. Out of these observations if the mean of first 13 observations is 32 and that of the last 13 observations is 40, the 13th observation is:

(A) 23

(B) 36

(C) 38

(D) 40

21. The median of the data

is

(A)

(B)

(C)

(D)

22. For drawing a frequency polygon of a continuous frequency distribution, we plot the points whose ordinates are the frequencies of the respective classes and abscissae are respectively:

(A) Upper limits of the classes

(B) Lower limits of the classes

(C) Class marks of the classes

(D) Upper limits of preceding classes

23. Median of the following numbers: is

(A) 4

(B) 5

(C) 6

(D) 7

24. Mode of the data is

(A) 14

(B) 15

(C) 16

(D) 17

25. In a sample study of 642 people, it was found that 514 people have a high school certificate. If a person is selected at random, the probability that the person has a high school certificate is:

(A)

(B)

(C)

(D)