The mean time taken to submit a project by a student was 25 days according to the previous semester record. The

Exam office claimed that this year the submission time increased due to the natural calamities. Was the submission

time really increased or not. Test the hypothesis with a 5% level of significance. The time taken by 20 students to

submit their project are given below (10+a), (15+b),(6+c),(17+d),18,19, (20+a), (21+b), (22+c), (23+d),24,25,(26+a),

(7+b), (8+c),(9+d),12,18,(0+a),(2+b).