Math Problem Solver

A random sample of 12 home internet users was selected from Telkom’s database and

their monthly internet usage (in hours) was identified for March last year (period 1) and

again for March this year (period 2). The data, together with the difference in matchedpairs data, xd

, is shown in Table 9.1.Table 9.1 Internet usage data (period 1 and period 2) and the difference measure (in hours)

Subscriber Period 1 Period 2 Difference

A 70 72 −2

B 85 84 1

C 64 68 −4

D 83 88 −5

E 68 68 0

F 91 95 −4

G 65 64 1

H 78 76 2

I 96 102 −6

J 92 94 −2

K 86 89 −3

L 73 75 −2

Note: The ‘Difference’ column is calculated by subtracting period 2’s data from period 1’s

data (i.e. xd

= x1 – x2). Therefore a negative difference implies an increase in usage from

period 1 to period 2 and a positive difference implies a decrease in usage from period 1 to

period 2.

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Chapter 9 – Hypothesis Testing: Comparison between Two Populations (Means and Proportions)

Management Question

Telkom’s internet marketing manager asked the question: ‘Is internet usage increasing?’

Conduct a hypothesis test, at the 5% significance level to determine if the monthly

internet usage per user has increased significantly from period 1 (March last year) to

period 2 (March this year).