Answer:
Step-by-step explanation:
We are given the following in the question:
The needle size should not be too big and too small.
The diameter of the needle should be 1.65 mm.
We design the null and the alternate hypothesis

Sample size, n = 35
Sample mean,
= 1.64 mm
Sample standard deviation, s = 0.07 mm
Type I error:
- It is the error of rejecting the null hypothesis when it is true.
- It is also known as false positive error.
- It is the rejecting of a true null hypothesis.
Thus, type I error in this study would mean we reject the null hypothesis that the average diameter is 1.65 mm but actually the average diameters of the needle is 1.65 mm.
Thus, average diameter is 1.65 mm and we decide that it is not 1.65 mm.
Answer: a) (1008.34,1019.658) b) (1009.24,1018.76)
Step-by-step explanation:
Since we have given that
n = 75
mean = 1014 hours
Standard deviation = 25 hours
At 95% two sided , z = 1.96
So, confidence interval would be

(b) Construct a 95% lower confidence bound on the mean life.
z = 1.65
So, confidence interval would be

Hence, a) (1008.34,1019.658) b) (1009.24,1018.76)
Okay so this is very easy so basically count the value of each coin then subtract to get *gets a call* hello? *other person starts talking* I just want you to know that the answer is 4 *hangs up* *starts talking* that was weird anyways the answer is four give
I wish I knew this one also