Answer:
b) The margin of error is approximately 3.24
e) The critical value is 1.7921.
Step-by-step explanation:
<u>Step(i</u>):-
Given sample size 'n' =20
Given sample standard deviation 's' = 10
<u><em> Margin of error </em></u>
<u><em>The margin of error is determined by</em></u>
<u><em /></u>
<u><em /></u>
<em>The level of significance ∝ =0.95</em>
<em>The degrees of freedom = n-1 = 20-1=19</em>
t₀.₉₅ = 1.729

Margin of error = 3.866
Step(ii):-
<u><em> Margin of error </em></u>
<u><em>The margin of error is determined by</em></u>
<u><em /></u>
<u><em /></u>
<u><em>Given another sample size n =30</em></u>
<em>The level of significance ∝ =0.95</em>
<em>The degrees of freedom = n-1 = 30-1=29</em>
t₀.₉₅ = 1.70

<u><em>Margin of error = 3.24</em></u>