Answer:
We can conclude that the experimental course effective at the alpha = 0.05 level of significance.
Step-by-step explanation:
Let p be the proportion of students from experimental course who complete the course with a letter grade of A, B, or C. Null and alternative hypotheses are:
H_0: p = 0.45
H_1: p > 0.45
Test statistic can be found using the equation
[tex]t=\frac{p(s)-p}{\sqrt{\frac{p*(1-p)}{N} } }[/tex] where
Then [tex]t=\frac{0.90-0.45}{\sqrt{\frac{0.45*0.55}{20} } }[/tex] ≈4.045
Since the one tailed 19 degrees of freedom p-value is ≈0.0003<0.05 we can conclude that the experimental course effective at the alpha = 0.05 level of significance.