Consider the system of inequalities
1. Plot all lines that are determined by equalities (see attached diagram)
2. Determine which bounded part of the plane you should select:
means that you should take points with y-coordinates greater than or equal to 2 (top part of the coordinate plane that was formed by the red line);
means that you should take points with x-coordinates less than or equal to 6 (left part of the coordinate plane that was formed by the blue line);- for
you can check where the origin is placed. Since 
, the origin belongs to the needed part and you have to take the right part of the coordinate plane that was formed by green line. - for
you can check where the origin is placed. Since 
, the origin belongs to the needed part and you have to take the bottom part of the coordinate plane that was formed by orange line.
3. According to the previous explanations, the shaded region is as in A diagram.
Answer: correct choice is A.
Answer:
B
Step-by-step explanation:
The central angle ANC is equal to the arc ABC that subtends it, thus
arc ABC = 138° → B
Answer:
a) The formula is given by mean 
the margin of error. Where the margin of error is the product between the critical value from the normal standard distribution at the confidence level selected and the standard deviation for the sample mean.
b) 
Step-by-step explanation:
Previous concepts
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
If the distribution for X is normal or if the sample size is large enough we know that the distribution for the sample mean 
is given by:
Part a
The formula is given by mean the margin of error. Where the margin of error is the product between the critical value from the normal standard distribution at the confidence level selected and the standard deviation for the sample mean.
Part b
The confidence interval for the mean is given by the following formula:
Answer:
52 dollars and 47 cents, or 52.47
Step-by-step explanation:
First, multiply 12 and 5.50, then you should get 66.00. Then, take the 25% discount, and divide it by a hundred, you should get 0.25, now multiply 0.25 and 66.00. You should get 16.50, thats your discount, so subtract 16.50 from 66.00, you should get 49.50. Now for the sales tax, divide 6.0 by 100, you should get 0.06. Now multiply 0.06 and 49.50, you should get 2.97, thats your tax, add it to 49.50, and you get 52.47 so BOOM, thats your answer, your welcome
