Answer:
Below is the solution to the given points:
Step-by-step explanation:
Please find the complete question in the attached file.
For point a:
[tex]H_0 : p \geq 0.90[/tex]
For point b:
[tex]z=\frac{\frac{x}{n}-p}{\sqrt{\frac{p(1-p)}{n}}}=\frac{\frac{215}{250}-0.90}{\sqrt{\frac{0.9 \times 0.10 }{250}}}= -2.11\\\\[/tex]
For point c:
[tex]Z_{critical} =z_{\alpha}=-1.28[/tex]
since the test statistics [tex]< Z_{critical}\\\\[/tex]
Reject [tex]H_o[/tex]
For point d:
[tex]P(|z \leq -2.11|)=0.0174[/tex]