Answer:
b) The width of the confidence interval becomes narrower when the sample mean increases.
Step-by-step explanation:
The confidence interval can be calculated as:

a) The width of the confidence interval becomes wider as the confidence level increases.
The above statement is true as the confidence level increases the width increases as the absolute value of test statistic increases.
b) The width of the confidence interval becomes narrower when the sample mean increases.
The above statement is false. As the sample mean increases the width of the confidence interval increases.
c) The width of the confidence interval becomes narrower when the sample size n increases.
The above statement is true as the sample size increases the standard error decreases and the confidence interval become narrower.
Answer:
The correct answer is:
Step-by-step explanation:
The given values are:
Service time varies,
Repair time = 2 hours
Standard deviation = 1.5 hours
Robotics uses per hour cost,
= $35
Company's cost per hour,
= $28
(a)
⇒ Arrival rate = Jobs per hours
then,
= 
= 
The jobs per hour will be:
⇒ 

(b)
⇒ Service rate = jobs per hour
then,
μ = 
= 
(2.6x7)/2
18.2/2
Area=9.1 m^2
Answer:
Not issue discussed plz full page