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.
Answer:
5.2
Step-by-step explanation:
ok so we need to find the unit rate( how many customers per minute) and thats 12 divided by 9 which is 1.3 minutes per customer so now we need to find what 1.3 minutes is x4 customers. This brings us to 5.2.
This is the answer and the steps
Answer:
Data: for the 10 days of practice, we have:
0.5 hours 1 time.
0.75 hours 2 times
1 hour 3 times
1.25 hours 2 times
1.5 hours 1 time
2 hours 1 time.
A) the largest amount number of times that she practiced by the same amount of time is 3 (for the 1-hour practice)
The smallest is 1 ( for the 0.5h, 1.5h, and 2h practices)
the difference is 3 - 1 = 2.
B) the time that she practiced more times is 1 hour, she practiced that amount of time in 3 different days out of the 10 days.
C) the equation can be found by multiplying the number of hours by the number of times that she practiced that amount of time, and then adding all of them:
0.5h*1 + 0.75h*2 + 1h*3 + 1.25h*2 + 1.5h*1 + 2h*1
D) the solution for the previous equation is 11 hours. Here the correct option is A.
