Answer: Null hypothesis = 5 days
Step-by-step explanation:
The null hypothesis attempts to show that no
variation exists between variables or that a single
variable is no different than its mean. It is
assumed to be true until statistical evidence
nullifies it for an alternative hypothesis.
Therefore null hypothesis equal to the mean of the variable.
The variable here is the claim processing time t
And the mean of the variable is 5 days.
Hence,
Null hypothesis = 5 days.
Goodluck...