Answer:
The 99% confidence interval for the true mean number of reproductions per hour for the bacteria is between 9.6 and 10.
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
So it is z with a pvalue of
, so 
Now, find the margin of error M as such

In which
is the standard deviation of the population and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 9.8 - 0.2 = 9.6 reproductions per hour.
The upper end of the interval is the sample mean added to M. So it is 9.8 + 0.2 = 10 reproductions per hour.
The 99% confidence interval for the true mean number of reproductions per hour for the bacteria is between 9.6 and 10.
Answer: if your question was C-A then it would be 2.42
Step-by-step explanation:
4.62-2.2
Answer:
The surface area is 150.
Step-by-step explanation:
To do this you need to find the area of one of the faces.
5*5=25
Then you should know that there are 6 faces.
25*6=150
A) The mean would be 1.842 and the standard deviation would be 1.339.
b) It would not be unusually low.
Explanationa) This can be modeled as a binomial distribution, since there are two outcomes (7 or not 7), the events are independent (getting a 7 on one spin does not influence the chance of a 7 on the next spin) and there are a fixed number of trials (70). In a binomial distribution, the mean is given by n*p, where n is the number of trials and p is the probability.
μ=n*p=70*(1/38) = 1.842.
The standard deviation of a binomial distribution is given by
σ=√(n*p*(1-p))=√(70(1/38)(37/38)=1.339.
b) To determine if this is unusually low, we find the probability:

Since this is not below 0.05, we do not consider this unusual.
8/10 and 80/100 are the same if simplified. So the answer would be the same.