Ya that's correct u got the right answer
Answer:
The 80% confidence interval for the mean number of toys purchased each year is between 7.5 and 7.7 toys.
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 
.
That is z with a pvalue of 
, so Z = 1.28.
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 7.6 - 0.1 = 7.5
The upper end of the interval is the sample mean added to M. So it is 7.6 + 0.1 = 7.7
The 80% confidence interval for the mean number of toys purchased each year is between 7.5 and 7.7 toys.
To get the answer to this problem, first we have to subtract the marked up cost to the cost of the product. So we first minus 25.3 and 22.25. When we do this, we will get a difference of 3.05. This is the profit that you will earn. So after that, we have to divide 3.05 and 25.30 to get the mark up percentage. When we do this, we will get an answer of 0.12. So in order to convert that into a percentage, we just have to multiply it by 100 and we will get 12%.
The formula for S.A. of a cylinder: S.A. = 2πr² + 2πrh (given).
r is radius, which is half the diameter. The diameter is 6 in, thus the radius is 3 in. h is height; the height of this cylinder is 8 in. Let's plug in our numbers and solve.
S.A. = 2π3² + 2π(3)(8)
S.A. = 2π9 + 2π24
S.A. = 18π + 48π
S.A. = 66π
Since the question says not to round, we must leave the answer in terms of pi.
Answer:
S.A. = 66π
