Answer:
The 80% confidence interval for the mean number of words a third grader can read per minute is between 40.4 wpm and 40.8 wpm.
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 40.6 - 0.2 = 40.4 words per minute.
The upper end of the interval is the sample mean added to M. So it is 40.6 + 0.2 = 40.8 words per minute.
The 80% confidence interval for the mean number of words a third grader can read per minute is between 40.4 wpm and 40.8 wpm.
With a square, all you need to do to find the length of one side is to divide the perimeter by 4. If it is the area you are calculating, then you need to find the square root. For that equation the answer is 24.
Answer:
Step-by-step explanation:
Let the area of water is w and area of land is l.
<u>Their ratio is:</u>
or
Find the value of l
- l = 133*3/7
- l = 57 million square miles
X+ 77.5 because if you subtract 25 from 180 you get 155. Then divide 155 by 2 and you get 77.5
Answer:
There is a plus sign between the n and 4. This cannot be reduced any further. So the answer that should go into the blank is Sum
Step-by-step explanation: