78% of all Millennials drink Starbucks coffee at least once a week. We speculate that this rate is lower among teenager in the US. A random sample of 40 teenagers was randomly selected and 60% said that they drink Starbucks coffee at least once a week. What distribution would you use to assess if the proportion of teenagers in the US who drink Starbucks coffee at least once a week is less compared to Millennials?

According to the sample size, it will be necessary to approximate the data through the normal distribution and through this calculate the standard deviation to obtain both the average, the standard deviation and the obtained deviation. Here the sample size is 40.

Approximately the distribution of proportion is a Normal distribution using the CLT. the mean will be 0.78, then we have that the standard deviation is,

Then the distribution will be normal with the values of 0.78 to 0.0655 for the mean and the standar deviation respectively.

Normal (0.78,0.0655)

step-by-step explanation:

you can add the two numbers and divide the result by 2. or you can find the gap between the two numbers and add half of this to the smaller number.

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