Answer:
The correct solution is "7.704". The further explanation is given below.
Step-by-step explanation:
According to the question,
[tex]t_{\alpha/2},df = 1.690[/tex]
Sample mean,
[tex]\bar{x} = \frac{(17.68 + 22.02)}{2}[/tex]
[tex]=19.85[/tex]
The Margin of error (E),
= [tex]Upper \ confidence \ interval - \bar{x}[/tex]
= [tex]22.02 - 19.85[/tex]
= [tex]2.17[/tex]
Now,
⇒ [tex]s = \frac{ E\times \sqrt n }{t_{\alpha/2},df}[/tex]
[tex]=\frac{ 2.17\times \sqrt 36 }{ 1.690}[/tex]
[tex]= 7.704[/tex]
