AQA AS Paper 2 2023 June — Question 18 3 marks

Exam BoardAQA
ModuleAS Paper 2 (AS Paper 2)
Year2023
SessionJune
Marks3
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicHypothesis test of binomial distributions
TypeInterpret test conclusion or error
DifficultyEasy -1.2 This is a straightforward hypothesis testing question requiring only standard recall of definitions. Part (a) asks for simple statement of H₀ and H₁ (routine bookwork), and part (b) asks for interpretation of a given result with no calculation needed. No problem-solving or novel application required—purely testing whether students know basic hypothesis test terminology and can write a contextual conclusion.
Spec2.05a Hypothesis testing language: null, alternative, p-value, significance2.05b Hypothesis test for binomial proportion

It is believed that 25% of the customers at a bakery buy a loaf of bread. In an attempt to increase this proportion, the manager of the bakery provided free samples for the customers to taste. To decide whether providing free samples had been effective, a large random sample of customers leaving the bakery were asked whether they had purchased a loaf of bread. A hypothesis test at the 5% significance level was carried out on the data collected. The test statistic calculated was found to be in the critical region.
  1. State the Null and Alternative hypotheses for this test. [1 mark]
  2. State, in context, the conclusion to this test. [2 marks]

Question 18:

AnswerMarks
18(a)States both hypotheses
correctly for a one-tailed test.
Accept equivalent in words.
Accept population proportion for
p.
Accept 25%, but not x = or x
AnswerMarks Guidance
= or µ =2.5 B1
0
H : p > 0.25
1
AnswerMarks Guidance
Subtotal1
QMarking instructions AO

AnswerMarks
18(b)Infers that that the Null
Hypothesis is rejected
AnswerMarks Guidance
PI by wording of the conclusion2.2b B1
suggest that the proportion of
customers buying a loaf of bread
has increased
Concludes correctly in context.
Must include ‘proportion’ OE,
not ‘probability’ or ‘number of’
‘Sufficient evidence’ OE
required.
Condone idea of causality if
AnswerMarks Guidance
suggested3.2a E1
Subtotal2
Question 18 Total3
QMarking instructions AO
Question 18:
--- 18(a) ---
18(a) | States both hypotheses
correctly for a one-tailed test.
Accept equivalent in words.
Accept population proportion for
p.
Accept 25%, but not x = or x
= or µ = | 2.5 | B1 | H : p = 0.25
0
H : p > 0.25
1
Subtotal | 1
Q | Marking instructions | AO | Marks | Typical solution
--- 18(b) ---
18(b) | Infers that that the Null
Hypothesis is rejected
PI by wording of the conclusion | 2.2b | B1 | There is sufficient evidence to
suggest that the proportion of
customers buying a loaf of bread
has increased
Concludes correctly in context.
Must include ‘proportion’ OE,
not ‘probability’ or ‘number of’
‘Sufficient evidence’ OE
required.
Condone idea of causality if
suggested | 3.2a | E1
Subtotal | 2
Question 18 Total | 3
Q | Marking instructions | AO | Marks | Typical solution
It is believed that 25% of the customers at a bakery buy a loaf of bread.

In an attempt to increase this proportion, the manager of the bakery provided free samples for the customers to taste.

To decide whether providing free samples had been effective, a large random sample of customers leaving the bakery were asked whether they had purchased a loaf of bread.

A hypothesis test at the 5% significance level was carried out on the data collected.

The test statistic calculated was found to be in the critical region.

\begin{enumerate}[label=(\alph*)]
\item State the Null and Alternative hypotheses for this test. [1 mark]

\item State, in context, the conclusion to this test. [2 marks]
\end{enumerate}

\hfill \mbox{\textit{AQA AS Paper 2 2023 Q18 [3]}}