Answer:
The graph in the attached figure
Step-by-step explanation:
we have

The solution of the inequality is the shaded area above the solid line of the equation of the parabola 
The vertex of the parabola is the point (0,-1)
The parabola open downward (vertex is a maximum)
using a graphing tool
see the attached figure
Answer:
D. Obtain a cluster sample by randomly selecting 20 counties and visiting every restaurant within those counties.
Step-by-step explanation:
Since this executive wants to minimize cost and expenses he should use a cluster sample of 20 counties and using the selected counties as a representative of the whole. Cluster sampling is a good and useful way of doing market research. It is more economical than other sampling methods and as the executive cannot get information on the whole population, he would be able to get information from the clusters.
Suppose the spinner lands on <em>a</em>. There's a 1/3 chance that it'll land on <em>a</em> the second time.
Suppose the spinner lands on <em>b</em>. There's a 1/3 chance that it'll land on <em>b</em> the second time.
Suppose the spinner lands on <em>c</em>. There's a 1/3 chance that it'll land on <em>c</em> the second time.
We've covered all possibilities for the first spin, and they're all equal, so their average is 1/3.
The probability that it'll land on the same letter twice is 33.3%.