A lecturer wants to know whether he has succeeded in teaching well or not. He said that his way of teaching works if the average score of students is 80. He only took scores from 10 students at random.

Student Grades. Source : MySkill.id

Hypothesis

$$ H_0 : \mu \le 80 $$

$$ H_1 : \mu \ge 80 $$

Critical point:

t = -2.03

t critical = 1.84

Formula

$$ t=\frac{\bar{X}- \mu}{S/\sqrt{n}} $$

Conclusion

T stat < T critical so is not enough evidence to reject H0. Student score ≤ 80

When our t_stat is not bigger than out t crisis, we can’t draw a conclusion that we can reject Hο.