Answer:
The 90% confidence interval for the true mean number of reproductions per hour for the bacteria is between 11.2 and 11.6 reproductions.
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 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 11.4 - 0.2 = 11.2 reproductions.
The upper end of the interval is the sample mean added to M. So it is 11.4 + 0.2 = 11.6 reproductions.
The 90% confidence interval for the true mean number of reproductions per hour for the bacteria is between 11.2 and 11.6 reproductions.
Answer: 
Work Shown:
I'm assuming your teacher wants you to factor as much as possible.
In the last step, I used the rule that 
We cannot factor any further. If the first term was 
instead of 
, then we could use the difference of squares factoring rule.
5³ is 5x5x5 so that is 125
120 pens for $24 is not a unit rate to describe this sale.
Answer:
There is a total of 66 different fruit salads.
Step-by-step explanation:
One fruit salad differs from the other only in the amount of pieces of certain fruit put in it. In order to easier denote fruit pieces we introduce these notations:
A-how many apples are put into the salad;
B-how many bananas are put into the salad;
C-how many cranberries are put into the salad.
Since she can freely choose the number of pieces of each fruit, we have these conditions for the variables A, B and C:
-
(she cannot choose a negative number of pieces) 
(because she can get the total of 10 pieces of fruit)
Another condition for forming the salad is that the salad must consist of exactly 10 pieces of fruit, hence we have this equation to solve:
but we must obtain the non-negative integer solutions of this equation.
That is equivalent to calculating the number of r-combinations of the multi-set S with objects of k different types with infinite repetition numbers.
The formula for obtaining the number of such r-combinations is:
We have that 
and that 
and we can observe the repetition number as infinite since she can create a fruit salad with only one piece of fruit and the repetition number in such cases is the maximum 10. Finally, we have that the total number of fruit salads equals:
.
