Apps. and Interpretation for IBDP Maths Ebook 1 | Page 358

Your Practice Set – Applications and Interpretation for IBDP Mathematics
3. The following table shows the nationality of 200 female students and X , the number of
dolls they own:
Nationality
Number of dolls own
1� X � 5 6 � X � 10 11� X � 15 Total
Colombia 35 15 13 63
Ecuador 24 28 12 64
Uruguay 41 17 15 73
Total a b 40 200
(a)
For the number of dolls own by students, write down
(i) the class mark of the class 6 � X � 10 ;
(ii) the lower class boundary of the class 6 � X � 10 ;
(iii)
the modal class.
(b) (i) Write down the values of a and b .
[3]
(ii) Write down the estimated mean of X .
(c)
A
(iii) Write down the estimated standard deviation of X .
A female student is selected at random. Find the probability that she is from
Colombia and owns at least six dolls.
2
� test for independence is conducted at a 5% significance level.
[4]
[2]
(d) (i) Write down the null hypothesis of the test.
(e)
(f)
(g)
(h)
(ii) Write down the alternative hypothesis of the test.
Write down the degree of freedom of the test.
Find the p -value.
Write down the value of
�
2
calc
, the test statistic.
State the conclusion of the test with a reason.
[2]
[1]
[2]
[1]
[2]
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