In an economics class, 4 students earned an A, 6 earned a B, 5 earned a C, 5 earned a D, and 3 earned an F. If a single student is picked at random, what is the probability that they earned an B or C?

Provide your answer as a simplified fraction.

We are given a system of equations,

[tex]\begin{cases}-x+2y=0\\y=-2\\ \end{cases}[/tex]

This will translate into a 2x2 matrix of coefficients (because 2 equations and 2 unknowns),

[tex]\begin{bmatrix}-1&2\\0&1\\ \end{bmatrix}[/tex]

The matrix will then be applied to the vector (lower dimensions on top),

[tex]\begin{bmatrix}x\\y\\ \end{bmatrix}[/tex]

And the result vector will be whats on the other side of equals sign,

[tex]\begin{bmatrix}0\\-2\\ \end{bmatrix}[/tex]

So to put everything together,

[tex]\begin{bmatrix}-1&2\\0&1\\ \end{bmatrix}\begin{bmatrix}x\\y\\ \end{bmatrix}=\begin{bmatrix}0\\-2\\ \end{bmatrix}[/tex]

Hope this helps :)

A cylinder is a three-dimensional structure formed by two parallel circular bases connected by a curving surface. The correct option is A.

A cylinder is a three-dimensional structure formed by two parallel circular bases connected by a curving surface. The circular bases' centers overlap each other to form a right cylinder.

The solid is described as a three-dimensional solid made from

two parallel and congruent discs, not in the same plane, and all the points

between them is a Cylinder.

Hence, the correct option is A.

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Answer:

[tex]14<15[/tex]

[tex]0<2x+10<62[/tex]

[tex]-10<2x<52[/tex]

[tex]-5<x<26[/tex]

~OAmalOHopeO

Answer:

1

Step-by-step explanation:

4x+6=10

4x=4

x=1

Answer:

[tex]4x + 6 = 10[/tex]

[tex]4x = 10 - 6[/tex]

[tex]4x = 4[/tex]

[tex]x = \frac{4}{4} [/tex]

[tex]x = 1[/tex]

hope this helps you

Answer:

The volume of this cone would be approximately equal to 2787.64 [tex]yd.^2[/tex].

Step-by-step explanation:

The formula used to calculate the volume of a cone is [tex]\pi r^2*\frac{h}{3}[/tex] where [tex]r[/tex] represents the radius of the circle at the base of the cone, and [tex]h[/tex] represents the vertical height of the cone. In this case, [tex]r[/tex] equals the diameter of the base divided by two, which is [tex]\frac{22}{2}[/tex] or 11 yards; and [tex]h[/tex] is equivalent to 22 yards. Insert these values into the formula and you'll get that the volume of this cone is equal to [tex]11^2*\pi*\frac{22}{3} = 121\pi * \frac{22}{3}[/tex] ≈ 2787.64 [tex]yd.^2[/tex], so that is the correct answer.

Answer:

(-2, 2)

Step-by-step explanation:

If you have a point (x, y) and you do a dilation by a scale factor K centered at the origin, the new point will just be (k*x, k*y)

So, if the original point is (-8, 8)

And we do a dilation by a scale factor k = 1/4

Then the image of the point will be:

(-8*(1/4), 8*(1/4))

(-8/4, 8/4)

(-2, 2)

Answer:

[tex]-\frac{x^{2} }{4}[/tex]  -2x - 7

Step-by-step explanation:

Never seen a phone with 3 cameras before or something but ok.

Took a while to use brainly's insert character thingie since fractions and the exponent kinda threw me off.

Every morning there are expected 240 customers who arrive at bank for the customer service.

There are on average 240 customers arriving to the bank every morning.

There are total 5 bank tellers and they take average 3 minutes to help customer.

The average time each bank teller spends on satisfying a customer will be calculated using the linear model,

Using wait time calculator:

Average service time / standard deviation

Ce = 3/1.5 = 2

The spent time on a customer is 3.4 minutes.

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Answer:

Customers spend 3.4 minutes in the bank on average.

Step-by-step explanation:

The customer arrives at the bank every morning. There is a line at bank goes to 5 bank teller. The customer takes 3 minutes with a 1.5-minute standard deviation.

The customer = 240

Time = 3

Where R = (240/4)

=60/hr

Where CVa = 1

Answer:

[tex]C=27inch\ by\ 27inch[/tex]

Step-by-step explanation:

Squares [tex]h=4inch[/tex]

Volume [tex]v=1444in^3[/tex]

Generally the equation for Volume of box is mathematically given by

 [tex]V=l^2h[/tex]

 [tex]1444=l^2*4[/tex]

 [tex]l^2=361[/tex]

 [tex]l=19in[/tex]

Since

Length of cardboard is

 [tex]l_c=19+4+4[/tex]

 [tex]l_c=27in[/tex]

Therefore

Dimensions of the piece of cardboard is

[tex]C=27inch\ by\ 27inch[/tex]

Answer:

√29

Step-by-step explanation:

This is due to A^2+b^2=c^2. you know that side a and b are 2 and 5, so it beocmes 25+4/=c^2, which means that 29=c^2, and you root it to get rid of the power of 2, so you obtain c=√29

this the answer of queastions

Step-by-step explanation:

67.18,68.82

Let mu be the true population mean of statistics exam scores. We have a large random samples of n=36 scores with a sample mean of 68.we know that the population standard deviation is sigma=3.A pivotal quantity is 3^sqrt(36)=(3/6)=68(1/2) which is approximately normally distributed. Therefore the 85%confidence interval is 68-(1/2)(1.6449), 68+(1/2)(1.6449) i.e (67.18,68.82)

Answer:

the distance between the ships is changing at 21.4 km/h

Step-by-step explanation:

Given;

distance between ship A and ship B = 150 km

speed of ship, A = 35 km/h

speed of ship B = 25 km/h

at 4 pm, the time difference = 4 hours

let the distance between A and B = C

The position of A after 4 hours = 35 km/h x 4 h = 140 km

The distance covered by A, a = 150 km - 140 km = 10 km

The distance covered by B, b = 25 km/h x 4 h = 100 km

The distance between A and B;

c² = a² + b²

c² = 10²  +  100²

c² = 10100

c = √10100

c = 100.5 km

The change in the distance between A and B is calculated as;

[tex]c^2 = a^2 + b^2\\\\2c\frac{dc}{dt} = 2a\frac{da}{dt} + 2b\frac{db}{dt} \\\\c\frac{dc}{dt} = a\frac{da}{dt} + b\frac{db}{dt} \\\\100.5(\frac{dc}{dt}) = -10(35) + 100(25) \\\\(the \ negative \ sign \ indicates \ decrease \ in \ distance \ of \ A \ from \ B \ with \ time)\\\\100.5(\frac{dc}{dt})= 2150\\\\\frac{dc}{dt} = \frac{2150}{100.5} \\\\\frac{dc}{dt} = 21.39 \ km/h\\\\\frac{dc}{dt} \approx 21.4 \ km/h[/tex]

Therefore, the distance between the ships is changing at 21.4 km/h

Answer:

your mom

Step-by-step explanation:

Hope the picture above will help you

P(even)=1/2. P(odd)=1/2. Let x= number of even in ten rolls

P(x<=8) = 1-P(x>=9) = 1-[C(10,9)(1/2)^9 *(1/2)^1 + C(10,10)(1/2)*(1/2)^0]

=1-[C(10,9)(1/2)^10 +C(10,10)(1/2)^10]

=1-(1/2)^10[10+1

=1–11/1024

=1013/1024

Answer:

8 1/8 units^3

Step-by-step explanation:

This figure is a rectangular prism, and the volume of a rectangular prism is given by the formula:

lwh

But since we have the area of the base snd the height of the figure, there is also one formula that we can use to find the volume:

bh

Which means area of base times the height.

USE THE FORMULA bh:

16 1/4 x 1/2

= 65/4 x 1/2

= 65/8

SIMPLIFIED: 8 1/8

Volume is measured in cubic units

SO YOUR ANSWER IS 8 1/8 units^3

Answer:

The graph would be compressed vertically by a factor of 1/3.

Step-by-step explanation:

Multiplying a function by some constant is a way to stretch or compress that function. If the magnitude of the constant is greater than 1, you are vertically stretching, if the magnitude of the constant is less than one but greater than 0 you are vertically compressing your function.

Answer:

The number is 448.

Step-by-step explanation:

Hope it helps

Answer:

Option C

Step-by-step explanation:

2 and 4 makes the figure look symmetrical

The required lines of symmetry are 2 and 4. option C is correct.

A given picture line of symmetry is to be determined from 1, 2, 3, and 4.

the line is a curve showing the shortest distance between 2 points.

A line of symmetry is defined as the line that draw across any curve or shape, The curve and shape have equal proportion across the line, that line is called the line of symmetry.

Clearly,  from observation, it is seen that line 1 and line 3 does not have the same proportion of area across it, so this is not a line of symmetry.
Line 2 and line 4, is lines of symmetry because it has equal proportion of the area across it.

Thus, the required lines of symmetry are 2 and 4. option C is correct.

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It does not appear that police can use a shoe print length to estimate the height of a​ male.

The given parameters are:

[tex]\begin{array}{cccccc}{Shoe\ Print} & {28.6} & {29.4} & {32.2} & {32.4} & {27.3} \ \\ Height (cm) & {172.5} & {176.7} & {188.4} & {170.1} & {179.2} \ \end{array}[/tex]

Rewrite as:

[tex]\begin{array}{cccccc}{x} & {28.6} & {29.4} & {32.2} & {32.4} & {27.3} \ \\ y & {172.5} & {176.7} & {188.4} & {170.1} & {179.2} \ \end{array}[/tex]

See attachment for scatter plot

To determine the correlation coefficient, we extend the table as follows:

[tex]\begin{array}{cccccc}{x} & {28.6} & {29.4} & {32.2} & {32.4} & {27.3} & y & {172.5} & {176.7} & {188.4} & {170.1} & {179.2} & x^2 & {817.96} & {864.36} & {1036.84} & {1049.76} & {745.29} & y^2 & {29756.25} & {31222.89} & {35494.56} & {28934.01} & {32112.64} & x \times y & {4933.5} & {5194.98} & {6066.48} & {5511.24} & {4892.16} \ \end{array}[/tex]

The correlation coefficient (r) is:

[tex]r = \frac{\sum(x - \bar x)(y - \bar y)}{\sqrt{SS_x * SS_y}}[/tex]

We have:

[tex]n =5[/tex]

[tex]\sum xy =4933.5+5194.98+6066.48+5511.24+4892.16 =26598.36[/tex]

[tex]\sum x =28.6+29.4+32.2+32.4+27.3=149.9[/tex]

[tex]\sum y =172.5+176.7+188.4+170.1+179.2=886.9[/tex]

[tex]\sum x^2 =817.96+864.36+1036.84+1049.76+745.29=4514.21[/tex]

[tex]\sum y^2 =29756.25+31222.89+35494.56+28934.01+32112.64=157520.35[/tex]

Calculate mean of x and y

[tex]\bar x = \frac{\sum x}{n} = \frac{149.9}{5} = 29.98[/tex]

[tex]\bar y = \frac{\sum y}{n} = \frac{886.9}{5} = 177.38[/tex]

Calculate SSx and SSy

[tex]SS_x = \sum (x - \bar x)^2 =(28.6-29.98)^2 + (29.4-29.98)^2 + (32.2-29.98)^2 + (32.4-29.98)^2 + (27.3-29.98)^2 =20.208[/tex]

[tex]SS_y = \sum (y - \bar x)^2 =(172.5-177.38)^2 + (176.7-177.38)^2 + (188.4-177.38)^2 + (170.1-177.38)^2 + (179.2-177.38)^2 =202.028[/tex]

Calculate [tex]\sum(x - \bar x)(y - \bar y)[/tex]

[tex]\sum(x - \bar x)(y - \bar y) = (28.6-29.98)*(172.5-177.38) + (29.4-29.98)*(176.7-177.38) + (32.2-29.98)*(188.4-177.38) + (32.4-29.98)*(170.1-177.38) + (27.3-29.98) *(179.2-177.38) =9.098[/tex]

So:

[tex]r = \frac{\sum(x - \bar x)(y - \bar y)}{\sqrt{SS_x * SS_y}}[/tex]

[tex]r = \frac{9.098}{\sqrt{20.208 * 202.028}}[/tex]

[tex]r = \frac{9.098}{\sqrt{4082.581824}}[/tex]

[tex]r = \frac{9.098}{63.90}[/tex]

[tex]r = 0.142[/tex]

Calculate test statistic:

[tex]t = \frac{r}{\sqrt{\frac{1 - r^2}{n-2}}}[/tex]

[tex]t = \frac{0.142}{\sqrt{\frac{1 - 0.142^2}{5-2}}}[/tex]

[tex]t = \frac{0.142}{\sqrt{\frac{0.979836}{3}}}[/tex]

[tex]t = \frac{0.142}{\sqrt{0.326612}}[/tex]

[tex]t = \frac{0.142}{0.5715}[/tex]

[tex]t = 0.248[/tex]

Calculate the degrees of freedom

[tex]df = n - 2 = 5 - 2 = 3[/tex]

The [tex]t_{\alpha/2}[/tex] value at:

[tex]df =3[/tex]

[tex]t = 0.248[/tex]

[tex]\alpha = 0.01[/tex]

The value is:

[tex]t_{0.01/2} = \±5.841[/tex]

This means that we reject the null hypothesis if the t value is not between -5.841 and 5.841

We calculate the t value as:

[tex]t = 0.248[/tex]

[tex]-5.841 < 0.248 < 5.841[/tex]

Hence, we do not reject the null hypothesis because they do not appear to have any correlation.

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Answer:

38.957625 US$

Step-by-step explanation:

38.957625 US$

Answer:

38.96

Step-by-step explanation:

Change from percent to decimal form

.0765 * 509.25

38.957625

Rounding to the nearest cent

38.96

[tex] \frac{5}{3} = \frac{12}{x} \\ = > \frac{5x}{3} = 12 \\ = > 5x = 12 \times 3 \\ = > 5x = 36 \\ = > x = \frac{36}{5} \\ = > x = 7.2[/tex]

This is the answer.

Answer:

115

Step-by-step explanation:

Since the lines are parallel, PWX+WXR=180, WXR=65. So PWX=(180-65)=115

Quadratic Formula: (-b +/- sqrt(b^2 - 4ac)) / 2a

2x^2 - 3x = 12

2x^2 - 3x - 12 = 0

a = 2

b = -3

c = -12

(--3 +/- sqrt( (-3)^2 - 4(2)(-12) )) / 2(2)

3 +/- sqrt( 9 + 96 ) / 4

3 +/- sqrt(105) / 4

Answers: [tex]\frac{3 + \sqrt{105} }{4}[/tex], [tex]\frac{3 - \sqrt{105} }{4}[/tex]

Hope this helps!

Answer:

24 boxes, 1 chocolate remaining

Step-by-step explanation:

289 chocolates total, each box is 12.

just divide it and whatever is left will be your remainder.

289/12 = 24 boxes, 1 chocolate remaining

sub to gauthmath sub reddit for more help like this !

Answer:

1  3 5 2 4 6

Step-by-step explanation:

Ans; [{(-90) + (-5)} 2-10] ×2 —> [{-90-5}2-10]×2 —> [{-95}2-10]×2 —> [-190-10]×2 —> [–200] ×2 —> = –400

I hope I helped you ^_^

Answer: 1.28571428571. This number is infinite.

Step-by-step explanation:

Answer:

1.29 rounded

Step-by-step explanation: