IB Maths AI SL 4.9 Normal distribution Question Bank
Practise IB Mathematics SL/HL 4.9 by applying normal distribution methods to exam-style questions.
- Syllabus
- First assessment 2021
- Course
- Mathematics: applications and interpretation SL
- Level
- SL
Practise IB Mathematics SL/HL 4.9 by applying normal distribution methods to exam-style questions.
A recent study found that the heights of Dutch women can be modelled by a normal distribution with mean 170.7 cm and standard deviation 6.3 cm .
A Dutch woman is chosen at random.
Calculate the probability that her height is
less than 160 cm .
P(X<160) OR labelled sketch of region O R calc syntax with correct bounds
(M1)
Note: Accept either zero or a large negative value as the lower bound.
between 160 cm and 170 cm .
27 % of Dutch women have a height of more than h metres.
P(160<X<170) OR labelled sketch of region O R calc syntax with correct bounds
(M1)
Note: Award A0A2 for answers of 0.045 and 0.41 both given to 2 sf.
Calculate the value of h.
P(X>h)=0.27 OR labelled sketch of region OR calc syntax with correct bounds
(M1)
=1.75( m)(1.74560…)
A1
Note: Accept 175 (cm).
Janneke selects a random sample of 200 Dutch women from Amsterdam and measures their heights. She wants to determine whether this sample could have been chosen from a normally distributed population with mean of 170.7 cm and standard deviation of 6.3 cm .
She performs a χ2 goodness of fit test at the 5 % significance level. She begins by creating the following frequency table.

Calculate, correct to four significant figures, the value of
a.
82.21
b.
The hypotheses for Janneke's test are
H0 : the heights are drawn from a normally distributed population with mean 170.7 cm and standard deviation 6.3 cm
H1 : the heights are not drawn from a normally distributed population with mean 170.7 cm and standard deviation 6.3 cm
94.86
Note: Follow through from an incorrect part (c)(i) if fourth value is found by subtracting first three values from 200. Award at most A0A1 if both answers are not given to four significant figures.
Marking guidance:
Award A0A1 for an answer of a=82.2 and b=94.8.