Grade 9 : Mathematics - 14. Statistics (Set 2)

Question 1

A student records their daily mathematics quiz scores for five consecutive days: $12, 15, 18, 11,$ and 14.

What is the mean score of the student over these 5 days?

Accepted Answer

B) 14

Answer

A) 12

Answer

C) 15

Answer

D) 16

Question 2

The daily maximum temperatures (in $^ ext{o} ext{C}$) recorded in a city over a week are: $22, 28, 19, 31, 25, 27,$ and 20.

What is the range of this temperature data?

Accepted Answer

C) $12^	ext{o}	ext{C}$

Answer

A) $10^	ext{o}	ext{C}$

Answer

B) $11^	ext{o}	ext{C}$

Answer

D) $15^	ext{o}	ext{C}$

Question 3

The heights (in cm) of 5 students are recorded as: $145, 150, 152, 155,$ and 160.

What is the median height of the group?

Accepted Answer

B) $152	ext{ cm}$

Answer

A) $150	ext{ cm}$

Answer

C) $155	ext{ cm}$

Answer

D) $160	ext{ cm}$

Question 4

The weights (in kg) of 6 athletes are: $42, 45, 48, 50, 52,$ and 55.

What is the median weight of the athletes?

Accepted Answer

B) $49	ext{ kg}$

Answer

A) $48	ext{ kg}$

Answer

C) $50	ext{ kg}$

Answer

D) $51	ext{ kg}$

Question 5

A shoe store manager logs the sizes of shoes sold during an hour: $6, 7, 8, 7, 9, 7, 8, 7$.

What is the mode of this shoe size dataset?

Accepted Answer

B) 7

Answer

A) 6

Answer

C) 8

Answer

D) 9

Question 6

What is the class mark of the class interval $20 - 30$?

Accepted Answer

B) 25

Answer

A) 20

Answer

C) 30

Answer

D) 50

Question 7

What is the class size (class width) for the class interval $40 - 55$?

Accepted Answer

B) 15

Answer

A) 10

Answer

C) 20

Answer

D) 95

Question 8

The mean of 5 observations $4, 7, 10, x,$ and 12 is 8. What is the value of $x$?

Accepted Answer

C) 7

Answer

A) 5

Answer

B) 6

Answer

D) 8

Question 9

Marks	10	20	30	40
Number of Students	4	6	8	2

Based on the frequency distribution table above, what is the total number of students surveyed?

Accepted Answer

B) 20

Answer

A) 18

Answer

C) 22

Answer

D) 100

Question 10

In the class interval $35 - 45$, what is the upper class limit?

Accepted Answer

C) 45

Answer

A) 35

Answer

B) 40

Answer

D) 10

Question 11

Marks	10	20	30	40
Number of Students	4	6	8	2

What is the cumulative frequency of the class interval $20 - 30$?

Accepted Answer

B) 13

Answer

A) 8

Answer

C) 20

Answer

D) 25

Question 12

What is the mean of the first 5 natural numbers?

Accepted Answer

C) 3

Answer

A) 2

Answer

B) 2.5

Answer

D) 3.5

Question 13

What is the mean of the first 5 prime numbers?

Accepted Answer

C) 5.6

Answer

A) 5.2

Answer

B) 5.4

Answer

D) 6.0

Question 14

In a histogram with equal class intervals, the area of each rectangular bar is proportional to which of the following?

Accepted Answer

B) Frequency of the corresponding class

Answer

A) Class size only

Answer

C) Cumulative frequency

Answer

D) Class mark

Question 15

Which of the following represents primary data?

Accepted Answer

C) Data collected directly by a teacher interviewing their students

Answer

A) Data collected from a published newspaper article

Answer

B) Data downloaded from a government official portal

Answer

D) Data taken from an encyclopedia

Question 16

When constructing a histogram with variable class widths, what formula is used to calculate the adjusted frequency (height of rectangle)?

Accepted Answer

A) $\frac{	ext{Frequency}}{	ext{Class size}} 	imes 	ext{Minimum class size}$

Answer

B) $\frac{	ext{Class size}}{	ext{Frequency}} 	imes 	ext{Minimum class size}$

Answer

C) $	ext{Frequency} 	imes 	ext{Class size}$

Answer

D) $\frac{	ext{Frequency}}{	ext{Total frequency}}$

Question 17

The mean of 10 numbers is 15. If 3 is added to every single number, what is the new mean?

Accepted Answer

B) 18

Answer

A) 15

Answer

C) 45

Answer

D) 12

Question 18

The mean of 6 observations is 20. If one observation 10 is removed, what is the mean of the remaining 5 observations?

Accepted Answer

C) 22

Answer

A) 20

Answer

B) 21

Answer

D) 24

Question 19

In continuous grouped data intervals $10 - 20, 20 - 30$, into which class interval is the value 20 included?

Accepted Answer

B) $20 - 30$

Answer

A) $10 - 20$

Answer

C) Both $10 - 20$ and $20 - 30$

Answer

D) Neither

Question 20

The mean of 5 numbers is 12. If each number is multiplied by 2, what is the new mean?

Accepted Answer

C) 24

Answer

A) 12

Answer

B) 14

Answer

D) 60

Grade 9 : Mathematics - 14. Statistics (Set 2)