Answer:
The claim is having statistical evidence.
Step-by-step explanation:
Given that faculty members at a large university are irritated by students’ cell phones. The faculty has found over the past several semesters that a cell phone rings in class on average 20 times per semester.
[tex]H_0: \bar x = 20\\H_a: \bar x <20[/tex]
(left tailed test at 5% confidence)
[tex]\bar x = 18.3\\s=2.7\\n = 19\\se = \frac{2.7}{\sqrt{19} } \\=0.6194[/tex]
Mean difference = -1.7
Test statitstic t = mean diff/std error = -2.744
df =18
p value = 0.006671
Since p < 0.05 we reject H0
The claim is having statistical evidence.