Answer: 1.684
Step-by-step explanation:
since sample size (n) is 41
confidence level = 0.90 = 90%
df = n - 1
df = 41 - 1
df = 40
that is For Degrees of Freedom = 40
significance level α = 1 - (confidence level / 100)
Significance Level α = 1 - (90/100 ) = 0.10
using the z-score
critical values of t = 1.684
A graph has been attached to further assist.