Note what i actually represents.
i is the very basis of a whole new level of counting. When finding discriminants, we often say that a quadratic has no
real roots if the discriminant is 0. Needless to say, there are roots, they are just imaginary.

, in real terms, is non-existent. That is, there are no numbers in the real number system that when multiplied by itself produces a result of -1. This is what i unit represents.
Let's tackle this problem in smaller steps.
Let's first expand our brackets.
(i - 7i)² = (-6i)² = 36i²
Now, let's distribute the xi.
xi(i - 7i)² = xi(36i²) = 36xi³ =

= -36xi
Answer:
The first box is 1 then 2 / 8 for the last
Step-by-step explanation:
It's:
1
-
8
Then
2
_
8
Because 4 x 2 = 8 for the denominator
and 1 x 2 = 2 for the numerator
Answer
Step-by-step explanation:
Done!
The test statistic for difference between two means is given by:

Thus, the appropriate test statistic is given by:

At 10% level of significance, the rejection region is given by

where:

for 10% level of significance is 1.65
Since z = 1.66 >

, we reject the null hypothesis, which means that <span>the traffic control strategy does not reduce carbon monoxide concentrations by at least 2 ppm.</span>