Answer:
[tex]\text{B)}H_0:X=19.7,\ H_a:X<19.7\\\\\text{C)} H_0:X=11.2,\ H_a:X<11.2[/tex]
Step-by-step explanation:
We know that the type of hypothesis test depends upon the nature of alternative hypothesis [tex]H_a[/tex] . If the alternative hypothesis is left-tailed then the test is also left-tailed.
Similarly for right tailed and two tailed hypothesis.
From the given options , the set of hypothesis with left-tailed alternative hypothesis are :-
[tex]\text{B)}H_0:X=19.7,\ H_a:X<19.7\\\\\text{C)} H_0:X=11.2,\ H_a:X<11.2[/tex]
Therefore , in choices B) and C) , the hypothesis test is left-tailed test.
