Answer:
c) .22
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 question:
Then
-48a÷ 8 can be written as,
Put a=1 in the above exprression and solve.
Therefore, the solution is -6.
Answer:
Step-by-step explanation:
in 1st figure
2:1=(x+2):2
2/1=(x+2)/2
4=x+2
x=2.
Similarly in the 2nd figure
8:5=(8+3):(5+x)
8/5 = 11/ (5+x)
8(5+x) =55
40+8x=55
8x=15
x=15/8
x=1.875
