Please, help me this due tomorrow morning I will mark as brainiest

To estimate μ, the mean salary of full professors at American colleges and universities, you obtain the salaries of a random sam

GenaCL600 [577]

Answer:

Step-by-step explanation:

The formula for calculating the confidence interval is expressed as;

CI = xbar ± z*s/√n

xbar is the sample mean = $73,220

z is the z score at 99% CI = 2.576

s is the standard deviation = $4400

n is the sample size = 400

Substitute the given values into the formula;

CI = 73,220 ± 2.576*4400/√400

CI = 73,220 ± 2.576*4400/20

CI = 73,220± (2.576*220)

CI = 73220±566.72

Hence a 99% confidence interval for μ is 73220±566.72

5 0

3 years ago

Determine the domain and range of the function f(x)= 3x+2. Also, state the intervals where the function f(x)= 3x+ 2 is increasin

aev [14]

Answer:

Increasing on it's domain $(-\infty,\infty)$ because the slope is positive.

The domain and range are both all real numbers, also known as

$(-\infty,\infty)$ .

Step-by-step explanation:

All domain really means is what numbers can you plug in and you get number back from your function.

I should be able to plug in any number into 3x+2 and result in a number. There are no restrictions for x on 3x+2.

The domain is all real numbers.

In interval notation that is $(-\infty,\infty)$ .

Now the range is the set of numbers that get hit by y=3x+2.

Well y=3x+2 is a linear function that is increasing. I know it is increasing because the slope is positive 3. I wrote out the positive part because that is the item you focus on in a linear equation to determine if is increasing or decreasing.

If slope is positive, then the line is increasing.

If slope is negative, then the line is decreasing.

So y=3x+2 hits all values of y because it is increasing forever. The range is all real numbers. In interval notation that is $(-\infty,\infty)$ .

3 0

3 years ago

Rochelle works part-time at the college museum, which pays her at a rate of $10 per hour. She also makes small bracelets that sh

katrin [286]

We know for our problem that Rachel makes $10 per hour. Since $x$ represent the number of hours that she works, $10x$ will be the total amount that she will make for working $x$ hours. We also know that she sells bracelets for $5 each. Since $y$ represents the number of of bracelets that she sells, $5y$ will be her total revenue for selling $y$ bracelets. We also know that she needs to earn at least $200 a week to cover her expenses, so the sum of $10x$ and $5y$ must be equal or greater than 200:

$10x+5 \geq 200$

We can conclude that <span>the graphs that shows the inequality that represents this situation, with its solution region shaded is:</span>