Answer:
The value is
Step-by-step explanation:
From the question we are told that
The sample mean is 
The sample size is n = 25
The standard deviation is 
Given that the sample size is not large enough i.e n< 30 we will make use of the student t distribution table
From the question we are told the confidence level is 99.7% , hence the level of significance is
=>
Generally the degree of freedom is 
=> 
=>
Generally from the student t distribution table the critical value of
at a degree of freedom of
is
Generally the margin of error is mathematically represented as
=>
=>
Gnerally the upper control chart limit for 99.7% confidence is mathematically represented as

=>
=>
Seeing from the graph I've provided above, the correct answer would be D, the last one.
Answer:
c
Step-by-step explanation:
hope this helps hœ
Do you need to find what t is? If so, do 300 divided by 60 to get the t isolated. which is, 5.
you can check by doing 60*5 which is 300