Explain why a sample of 30 dentists from a large city taken to estimate the median income of all residents of that large city is not representative

Because all individuals in the sample have the same job, so the sample is biased.

Step-by-step explanation:

Ignoring the fact that 30 is a small sample for a large city, we already know that all the people in the sample has the same profession.

Now, we can expect that two dentists win have around the same income, but not all the residents in the city are dentists

A lot of them work in fast food, others may be lawyers, others may be freelancers.

We have a lot of jobs where the income does not coincide with the average income of a dentist, so with the sample of 30 dentists we are not actually representing all the other possible jobs that there are in the city.

If we want a sample that represents the income of all the residents, we should have a random sample (so the sample is not biased, like in this case).

let's cover over the formula of the vertex:

y = a(x – h)^2 + k

in this formula, (h,k) are the vertex, always remember that the positive or negative value of the vertex is based on the sign it has.

for example, if the vertex is -3,-6 then both the x and y value would have the positive sign attached to it and if it were a positive x and y value, then a negative sign would be attached to it.

with that being said, for our problem the x value is a positive one so we are looking for a number with a negative sign next to it, in this case the first and second choice.

however, for the first answer choice it isn't quite part of the formula so we know that the answer choice correctly displays the x value.

to confirm, we can see if the -1 fits correctly with the second answer choice, and as mentioned above a negative number will have a positive sign attached to it. so, for our problem we can see that -1 has been changed to +1, so we can confirm that the second answer choice is correct.

hence, our final answer is y=(x - 1)^2 + 1

circumference divided by 3.141592654 then timesthe radius twice

step-by-step explanation:

circumference divided by 3.141592654 then timesthe radius twice