Answer:
Step-by-step explanation:
drain empties 1/10 of the desired amount per minute
pump fills 1/14 of the desired amount per minute
when both are active, the net drain is 1/10-1/14 = 1/35 of the desired amount per minute
It takes 35 minutes to reach the cut-off level.
Answer:
A 90% confidence interval for the mean number of letter sounds identified in one minute is: (30.84, 37.34).
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 = 1.645.
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 34.09 - 3.25 = 30.84.
The upper end of the interval is the sample mean added to M. So it is 34.09 + 3.25 = 37.34.
A 90% confidence interval for the mean number of letter sounds identified in one minute is: (30.84, 37.34).
Answer:
1. x - 1
2. 
Step-by-step explanation:


Answer:
The standard form of a circle's equation is (x-h)² + (y-k)² = r² where (h,k) is the center and r is the radius.
Step-by-step explanation: