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SL 4.1—Concepts, reliability and sampling techniques - IB Questionbank | RevisionDojo

Practice SL 4.1—Concepts, reliability and sampling techniques with authentic IB Mathematics Analysis and Approaches (AA) exam questions for both SL and HL students. This question bank mirrors Paper 1, 2, 3 structure, covering key topics like functions and equations, calculus, complex numbers, sequences and series, and probability and statistics. Get instant solutions, detailed explanations, and build exam confidence with questions in the style of IB examiners.

Paper

Level

Question 1

SL & HLPaper 1

Here are the heights, in cm, of $7$ plants:

$25, 22, 28, 20, 26, 21, 23$

Find the median height.

[1]

A sack contains $8$ potatoes. The mean mass of the potatoes is $120$ g. One potato is removed from the sack. The mean mass of the remaining $7$ potatoes is $115$ g. Work out the mass of the potato that was removed.

[2]

Question 2

SL & HLPaper 1

A small group of students recorded the number of hours they spent studying for a test: $2, 3, 5, 2, 4, 3, 2$ .

Find the mean number of hours.

[1]

Find the median number of hours.

[1]

Find the mode number of hours.

[1]

Question 3

SL & HLPaper 1

A student took three quizzes. Her mean score was $7$ . Her median score was $6$ . Her highest score was $8$ marks more than her lowest score.

Find the number of marks she scored in each of the three quizzes.

[3]

The student took a fourth quiz. The mean of her four scores was $9$ marks. Find the number of marks that the student scored in the fourth quiz.

[3]

Question 4

SL & HLPaper 1

The scores of $25$ students on a short mathematics quiz are summarized in the frequency table below:

Score (x)	0	1	2	3	4	5
Frequency (f)	2	4	7	6	4	2

Find the lower quartile ( $Q_1$ ) of the scores.

[2]

Find the upper quartile ( $Q_3$ ) of the scores.

[2]

Calculate the interquartile range (IQR).

[2]

Question 5

SL & HLPaper 1

The number of customers served by a shop assistant each hour over a $10$ -hour period is shown below:

$8, 12, 10, 9, 15, 11, 8, 10, 12, 9$

Find the median number of customers served.

[2]

Calculate the mean number of customers served.

[2]

Suppose the largest value, $15$ , was mistakenly recorded as $25$ . Explain how this correction would affect the mean and median calculated in parts (a) and (b).

[4]

Question 6

SL & HLPaper 1

A group of four numbers has a mean of $7$ and a median of $6$ . The numbers $4$ and $10$ are added to the group.

Find the mean of the six numbers.

[2]

Find the median of the six numbers.

[2]

Question 7

SL & HLPaper 1

A meteorological station recorded the deviation from the average temperature, in $^\circ$ C, at 10 different times during a day. The results are given below: $-5, -3, -1, 0, 1, 2, 3, 3, 4, -4$

For these results, find the median.

[2]

For these results, find the mean.

[2]

Later, two additional readings were recorded. When these two new readings were included, the new mean for all 12 readings became $0.5^\circ$ C, and the new median became $1^\circ$ C. Find the two new readings.

[4]

Question 8

SL & HLPaper 1

Consider four integers $a$ , $b$ , $c$ , and $d$ such that $a<b<c<d$ .

Let $a<b<c<d$ where the maximum is twice the range, and the median is 10. Find the value of $a$ for which the mean is 11.

[4]

Let $a$ and $d$ be the same as your answers to part (a), but $b$ and $c$ have been altered. If $a,b,c,d$ create a geometric sequence, find the median.

[4]

Question 9

SLPaper 1

Consider three integers $a$ , $b$ , $c$ which follow an arithmetic sequence respectively.

Show that $b$ is the mean of $a$ and $c$

[2]

if $2b$ is the range, find $a$

[2]

A student said that this forms a geometric sequence of common ratio 2, is that correct? Explain why or why not.

[2]

Question 10

SL & HLPaper 2

A survey was conducted on $40$ students about the number of books they read in a month. The results are shown in the table, where $k$ is an unknown frequency.

Number of books (x)	0	1	2	3	4	5
Frequency (f)	4	10	k	9	5	3

If the mean number of books read is $2.25$ , find the value of $k$ .

[4]

Calculate the median number of books read.

[2]

The survey was extended to include $10$ more students. It was found that $4$ of these students read $0$ books, and $6$ students read $1$ book. Calculate the new mean number of books read for all $50$ students.

[3]

After the original survey of the $40$ students (with the value of $k$ found in (a)), it was discovered that one student who was recorded as having read $4$ books had actually read $0$ books.

(i) Calculate the new mean number of books for the $40$ students after this correction.

(ii) Without further calculation, state and explain whether the standard deviation will increase or decrease due to this correction.

[4]

SL 4.1—Concepts, reliability and sampling techniques Questionbank