Angelina's null hypothesis (H0) would be that the proportion of engineering students who do not own a calculator is still 0.15. Her alternative hypothesis (Ha) would be that the proportion is less than 0.15.
H0: p = 0.15
Ha: p < 0.15
Angelina's calculated p-value of 0.198 is greater than her significance level of 0.05. Therefore, she fails to reject the null hypothesis. She cannot conclude that the proportion of engineering students who do not own a calculator has decreased from the previous years.