Answer:
The claim is not true
Step-by-step explanation:
We are given that A local retailer claims that the mean waiting time is less than 8 minutes.
A random sample of 20 waiting times has a mean of 6.3 minutes with a standard deviation of 2.1 minutes.
s = 2.1
n = 20
Since n <30 and population standard deviation is unknown
So,we will use t test
So,
t=-3.62
α = 0.01
Degree of freedom = df=n-1=20-1=19
t calculated < t critical
So, we failed to reject null hypothesis
Hence the claim is not true