Answer:
The distribution of average life time is approximately normallyl distributed with mean 20 hours and standard deviation of 0.4743 hours
Step-by-step explanation:
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean 
and standard deviation 
, the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean and standard deviation 
.
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
In this problem
The distribution of average life time is approximately normallyl distributed with mean 20 hours and standard deviation of 0.4743 hours
Answer:
-2
Step-by-step explanation:
Subtracting a negative number is the same as adding it, so this is basically just negative 8 plus 6, which is -2. Don't know who was right though, you kinda left that part of the question out.
Answer:
licensed drivers who makes calls while driving
Step-by-step explanation:
Answer:
(4.5, 4.7)
Step-by-step explanation:
Hi!
Lets call X to the consumption of milk per week among males over age 32. X has a normal distribution with mean μ and standard deviation σ.
When you know the population standard deviation σ of X , and the sample mean is 
, the variable q has distribution N(0,1):
Then you have:
This defines a C - level confidence interval. For each C the value of k is well known. In this case C = 0.98, then k = 2.326
Then the confidence interval is:
