Evaluate the expression 120n + 160,500 when n= 32. n=_____

If 40% of a number is 80 what is 25% of that number?

olga2289 [7]

Answer:

25% of 200 is 50

Step-by-step explanation

40% of a number is 80

.40 * n = 80

Divide each side by .4

.40 n/.4 = 80/.4

n = 200

The number is 200

Now lets find 25 percent of that number

.25 * 200 = 50

7 0

3 years ago

In an examination of purchasing patterns of shoppers, a sample of 16 shoppers revealed that they spent, on average, $54 per hour

Lesechka [4]

Answer:

$54-1.64\frac{21}{\sqrt{16}}=45.39$

$54 +1.64\frac{21}{\sqrt{16}}=62.61$

So on this case the 90% confidence interval would be given by (45.39;62.61)

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".

$\bar X=54$ represent the sample mean

$\mu$ population mean (variable of interest)

$\sigma=21$ represent the sample standard deviation

n=16 represent the sample size

Solution to the problem

The confidence interval for the mean is given by the following formula:

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

Since the Confidence is 0.90 or 90%, the value of $\alpha=1-0.9=0.1$ and $\alpha/2 =0.05$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.05,0,1)".And we see that $z_{\alpha/2}=1.64$

Now we have everything in order to replace into formula (1):

$54-1.64\frac{21}{\sqrt{16}}=45.39$

$54 +1.64\frac{21}{\sqrt{16}}=62.61$

So on this case the 90% confidence interval would be given by (45.39;62.61)

4 0

3 years ago

7 + 2y^2 Evaluate the expression for Y = 5. Please help me

garik1379 [7]

Answer:

107

Step-by-step explanation:

We first need to input the values of the variables.

7 + 2 x 5^2

7+10^2

7+100 = 107

4 0

2 years ago

What is the solution set? (0, -2) (2, 0) (7, 0) (5, 3)

Dvinal [7]

Answer:

(5,3)

Step-by-step explanation:

Look for the coordinates of the point of intersection where the 2 graphs cross. This gives the solution.

In this case, they cross at (5,3) and they intersect at only one location (i.e there is only 1 solution)

7 0

2 years ago

Read 2 more answers

What is the slope of the line?

spin [16.1K]

Answer:

-7/2

Step-by-step explanation:

The slope of a line can be defined as: $\frac{rise}{run}$ , which can be more formally calculated as: $\frac{y_2-y_1}{x_2-x_1}$ , where it's essentially the same thing, except the rise/run is being calculated with two points (which you already need)

So let's just say: $(x_1, y_1)=(-5, 5)\text{ and } (x_2, y_2)=(-3, -2)$

Plugging the values into the equation we get: $\frac{-2-5}{-3-(-5)}\implies\frac{-7}{-3+5}\implies-\frac{7}{2}$

You can also just look at the graph and see that from point 1 to point 2, it "rised" -7 units, and "ran" 2 units.

Notice how the "rise" is negative? That just means it went down.

4 0

9 months ago

Evaluate the expression 120n + 160,500 when n= 32. n=______