Apps. and Interpretation for IBDP Maths Ebook 1 | Page 352

Your Practice Set – Applications and Interpretation for IBDP Mathematics
(c)
(d)
Find the p -value.
State the conclusion of the test with a reason.
[2]
[2]
3. The table below shows the typing speed (words per minute) of a group of students in a
vocational training school before and after training:
Typing speed
before training
(words per minute)
Typing speed
after training
(words per minute)
38 32 37 40 15 18 29 23
40 46 56 51 30 20 37 40
The curriculum development officer of the school wants to investigate whether the
students show improvement after training. Let �
1
and �
2
be the mean typing speeds of
students before and after training respectively. A t -test is conducted at a 5% significance
level, and it is assumed that the variances of the typing speeds for two data sets are the
same.
(a)
(b)
(c)
(d)
Write down the alternative hypothesis of the test.
Find the p -value.
Write down the value of t , the t -statistic.
State the conclusion of the test with a reason.
[1]
[2]
[1]
[2]
4. Two surveys are conducted to measure the students’ satisfaction on the services provided
by the tuck shop. A score from 0 to 10 is used in the surveys, where 0 represents absolute
dissatisfaction and 10 represents absolute satisfaction. The table below shows the results
of the surveys:
Scores from the
first survey
Scores from the
second survey
8 10 8 9 10 6 3 10
10 10 7 10 9 6 5
The student union committee members want to investigate whether the mean scores of
the two surveys are different. Let �
1
and �
2
be the mean scores of the first survey and
the second survey respectively. A t -test is conducted at a 10% significance level, and it is
assumed that the variances of the scores from two surveys are the same.
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