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Date May Example question Marks available 3 Reference code EXM.1.AHL.TZ0.59
Level Additional Higher Level Paper Paper 1 Time zone Time zone 0
Command term Calculate Question number 59 Adapted from N/A

Question

The heights, xx metres, of the 241 new entrants to a men’s college were measured and the following statistics calculated.

x=412.11,x2=705.5721x=412.11,x2=705.5721

The Head of Mathematics decided to use a χ2χ2 test to determine whether or not these heights could be modelled by a normal distribution. He therefore divided the data into classes as follows.

Calculate unbiased estimates of the population mean and the population variance.

[3]
a.

State suitable hypotheses.

[1]
b.i.

Calculate the value of the χ2χ2 statistic and state your conclusion using a 10% level of significance.

[11]
b.ii.

Markscheme

ˉx=412.11241=1.71¯x=412.11241=1.71            A1

s2=705.5721240412.112240×241=0.0036s2=705.5721240412.112240×241=0.0036        M1A1

[3 marks]

a.

H0: Data can be modelled by a normal distribution

H1: Data cannot be modelled by a normal distribution           A1

[1 mark]

b.i.

The expected frequencies are

       A1A1A1A1A1A1

χ2=528.04+34230.19++12216.10241=3.30/3.29χ2=528.04+34230.19++12216.10241=3.30/3.29       M1A1

Degrees of freedom = 3       A1

Critical value = 6.251 or p-value = 0.35       A1

The data can be modelled by a normal distribution.       R1

[11 marks]

b.ii.

Examiners report

[N/A]
a.
[N/A]
b.i.
[N/A]
b.ii.

Syllabus sections

Topic 4—Statistics and probability » SL 4.9—Normal distribution and calculations
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Topic 4—Statistics and probability

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