Answer:

Step-by-step explanation:
Solve like a normal equation by isolating the variable and then dividing by the coefficient.

Factor because if we have
yz=0 then we can assume y and/or z=0
so factor
so the easiest way is to find what 2 numbers add to -6 and multiply to get 9 so
we know that they must be both - because we must have x+x=(-) and x^2=+ so therefor they must be negative
factors of 9=3 and 3 so
-3 and -3
-3+-3=-6 perfect
(z-3)(z-3)=0
set each to zero
z-3=0
add 3
z=3
z=3 is the answer
Answer:
a) 
b) The should sample at least 293 small claims.
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
, which means that the answer of question a is 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.
(b) If the group wants their estimate to have a maximum error of $12, how many small claims should they sample?
They should sample at least n small claims, in which n is found when
. So







The should sample at least 293 small claims.