Answer:
Our decision rule will be to reject The null hypothesis H0 if the test statistic is less than -1.645, or if it is greater than +1.645.
Step-by-step explanation:
The hypotheses would be;
Null hypothesis;H0: μ = 500
Alternative hypothesis;Ha: μ ≠ 500
Since it's two - tailed at 0.1 level of significance, then each tail will contain 5% or 0.05. From the z-table attached, the corresponding critical value of 0.05 is approximately 1.645 standard deviations from the mean.
Thus, our decision rule will be to reject The null hypothesis H0 if the test statistic is less than -1.645, or if it is greater than +1.645.
Answer:

Step-by-step explanation:
1) if the point A has coordinates (-1;10) and the point B - (5;2), then it is possible to write common view of the required equation of the line:

2) if to substitute the coordinates of A&B into the common equation, then:

3) finally, in slope-intersection form:
3y= -4x+26; ⇔ y= -4/3 x +26/3.
P.S. the suggested way of the solution is not the only one.
Answer:
121 smokers
Step-by-step explanation:
This can be calculated as a simple rule of 3.
In these problems, the first step is identifying the measures in the problem. Then, we must identify whether their relation is direct or inverse.
When it is direct, as one measure increases, the other will increase too.
When it is inverse, as one measure increases, the other will decrease.
In this problem, the measures are the number of people over 12 that smoke, and the total number of people over 12. Their relation is direct, because as the number of people increases, the number of smokers will increase too.
So we must solve the following rule of three:
22 smokers - 100 people
x smokers - 550 people
x = 550*22/100
x = 22*5.5
x = 121 smokers.
So, in a group off 550 people over the age of 12, there are 121 expected smokers.
x³+2x²-6x-12=x²•(x+2)-6(x+2)=(x+2)•(x²-6)