The average cost to own and operate a car in the United States for 2020 was $0.524 per mile.

Out of the 25 students in Mrs. Coulter's class, 15 are girls. In the school there are 390 boys. If the ratio of boys to students

GREYUIT [131]

Answer:

975 students

Step-by-step explanation:

This is a dense question. Let's look at it piece by piece:

1. The ratio of boys to students in the class is 10/25. If there are 25 students and 15 girls, that leaves 10 boys.

2. The question says that the ratio is in proportion of boys to total students in the school. "In proportion" in this case means that if we convert 10/25 to a fraction with numerator 390, the denominator is the amount of students in school.

3. 10x39=390. What you do the numerator you must do to the denominator: 25x39=975.

4. This means 975 students go to the school.

6 0

2 years ago

Read 2 more answers

Algebraic Reasoning please help!

stiv31 [10]

Answer:

$\left[\begin{array}{ccc}7\\4\\2\end{array}\right]$

The answer is a single-column matrix (7,4,2)

Step-by-step explanation:

In such multiplication of matrices, you have to proceed by multiplying each ROW of the first matrix by the COLUMN of the second matrix. So,

$\left[\begin{array}{ccc}3&6&1\end{array}\right] * \left[\begin{array}{ccc}2\\0\\1\end{array}\right] = (3 * 2) + (6 * 0) + (1 * 1) = 6 + 0 + 1 = 7$

then...

$\left[\begin{array}{ccc}2&4&0\end{array}\right] * \left[\begin{array}{ccc}2\\0\\1\end{array}\right] = (2 * 2) + (4 * 0) + (0 * 1) = 4 + 0 + 0 = 4$

and

$\left[\begin{array}{ccc}0&6&2\end{array}\right] * \left[\begin{array}{ccc}2\\0\\1\end{array}\right] = (0 * 2) + (6 * 0) + (2 * 1) = 0 + 0 + 2= 2$

I hope it helps.

5 0

3 years ago

A fast food restaurant executive wishes to know how many fast food meals teenagers eat each week. They want to construct a 99% c

Lana71 [14]

Answer:

The minimum sample size required to create the specified confidence interval is 2229.

Step-by-step explanation:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1-0.99}{2} = 0.005$

Now, we have to find z in the Ztable as such z has a pvalue of $1-\alpha$ .

So it is z with a pvalue of $1-0.005 = 0.995$ , so $z = 2.575$

Now, find the margin of error M as such

$M = z*\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

What is the minimum sample size required to create the specified confidence interval

This is n when $M = 0.06, \sigma = 1.1$

$0.06 = 2.575*\frac{1.1}{\sqrt{n}}$

$0.06\sqrt{n} = 2.575*1.1$

$\sqrt{n} = \frac{2.575*1.1}{0.06}$

$(\sqrt{n})^{2} = (\frac{2.575*1.1}{0.06})^{2}$

$n = 2228.6$

Rounding up

The minimum sample size required to create the specified confidence interval is 2229.

7 0

3 years ago

How did I get a 2 here (simplifying ratios)

PilotLPTM [1.2K]

Answer:

$\frac{2x {}^{2} + 14x + 24 }{4 {x}^{2} + 4x - 48 } = \frac{x + 4}{2(x - 2)}$

Step-by-step explanation:

Please see attached picture for full solution.

4 0

3 years ago

Basically almost finished it just stuck on the last part. The angle of elevation to a nearby tree from a point on the ground is

Studentka2010 [4]

Answer:

12.4 ft

Step-by-step explanation:

Everything is done right so far.

Now to calculate the height of the tree, 12tan46, put the equation into a calculator.

Either a graphing calculator (make sure it is in degrees, not radians),

or the one on your phone (turn your phone landscape in the calculator app to get the trig functions.))

12tan46= 12.4 ft

4 0

2 years ago