Answer:
D
Step-by-step explanation:
The other ones don't make sense. The answer is 3.5x+x=9.90
Answer:
B. 97%
Step-by-step explanation:
20 students is -2 standard deviations away from the mean
35 is +3 standard deviations away from the mean
100 - 2.4 = 97.6
(2.4 is amount of data we are not using)
please refer to the standard deviation graph attached :)
Answer:
1.165.
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 the margin of error M as such
In which 
is the standard deviation of the population and n is the size of the sample.
In this problem, we have that:
. So
So the correct answer is:
1.165.
x + 4 = 15
- 4 -4
x = 11
You would subtract 4 because you need to isolate the x to get the value of x. You would subtract it to both sides because whatever you do on one side, you have to do it to the other side.
Answer:
Then, a=-1 and b=-1
Step-by-step explanation:
We need to solve the following system of equations using the adition method:
2a+3b=-1 (i)
3a+5b=-2 (ii)
First, we multiply the equation (i) by -3 and the equation (ii) by 2, so we get:
-6a-9b=3
6a+10b=-4
Adding the two equations we have:
-6a-9b=3
6a+10b=-4
--------------------------
0 + b = -1
Then b=-1. Now, let's substitute the value of b into equation (i):
2a+3b=-1
2a + 3(-1) = -1
2a -3 = -1
2a = 2
a = 1
Then, a=-1 and b=-1
