Homework: Section 1.2 Applications Linear
Score: 0 of 1 pt
8 of 10 (7 complete)
1.2.31
How many quarts of pure antifreeze must be added to 4 quarts of a 10% antifreeze solution to obtain a 20% antifreeze solution?
quart(s) of pure antifreeze must be added.
(Round to the nearest tenth as needed)

Answer:

Step-by-step explanation:

This is a test of 2 independent groups. The population standard deviations are not known. Let μ1 be the mean GPA of night students and μ2 be the mean GPA of day students.

The random variable is μ1 - μ2 = difference in the mean GPA of night students and the mean GPA of day students.

We would set up the hypothesis.

The null hypothesis is

H0 : μ1 = μ2 H0 : μ1 - μ2 = 0

The alternative hypothesis is

H1 : μ1 ≠ μ2 H1 : μ1 - μ2 ≠ 0

This is a two tailed test.

Since sample standard deviation is known, we would determine the test statistic by using the t test. The formula is

(x1 - x2)/√(s1²/n1 + s2²/n2)

From the information given,

μ1 = 2.35

μ2 = 2.58

s1 = 0.46

s2 = 0.47

n1 = 30

n2 = 25

t = (2.35 - 2.58)/√(0.46²/30 + 0.47²/25)

t = - 1.8246

The formula for determining the degree of freedom is

df = [s1²/n1 + s2²/n2]²/(1/n1 - 1)(s1²/n1)² + (1/n2 - 1)(s2²/n2)²

df = [0.46²/30 + 0.47²/25]²/[(1/30 - 1)(0.46²/30)² + (1/25 - 1)(0.47²/25)²] = 0.00025247091/0.00000496862

df = 51

We would determine the probability value from the t test calculator. It becomes

p value = 0.0746

Since alpha, 0.05 < than the p value, 0.0746, then we would fail to reject the null hypothesis.

Answer:

  65°

Step-by-step explanation:

Short arc AC is the difference between 360° and long arc ABC:

  arc AC = 360° -230° = 130°

The inscribed angle ABC that intercepts this short arc will have half the measure of the arc:

  ∠ABC = 130°/2 = 65°

Answer:

B. 0.0043

Step-by-step explanation:

The null and alternative hypothesis of this one-tailed test are:

[tex]H_0: p_1-p_2=0\\\\H_a:p_1-p_2> 0[/tex]

The output of proportions_ztest method from statsmodels is a size-2 vector with the value of the test statistic and the P-value.

Then, if the output is (3.25, 0.0043), the P-value for this one-tailed test is 0.0043.

Answer:

Step-by-step explanation:

line equation:  y=mx + C

substitute given values

-7 = -3*0 + C

C=y= -7      ANS

Answer:

[tex]a^{\frac{9}{2}}[/tex]

Step-by-step explanation:

[tex]\left(a^{\frac{3}{2}}\right)^3[/tex]

[tex]=a^{\frac{3}{2}\cdot \:3}[/tex]

[tex]=a^{\frac{3}{2}\cdot \frac{3}{1}}[/tex]

[tex]=a^{\frac{9}{2}}[/tex]

Answer: B. although none are exactly 0.3 B is closest

Step-by-step explanation:

a. 35/999 = .0350

b. 31/99 = .3153

c. 105/7333 = .0143

d. 35/111 = .3135

Answer:

Part a

Null hypothesis: [tex] \mu = 69.3[/tex]

Alternative hypothesis: [tex]\mu \neq 69.3[/tex]

Part b

[tex] z = \frac{69.8- 69.3}{\frac{11.2}{\sqrt{140}}}= 0.528[/tex]

Step-by-step explanation:

For this case we have the following info given :

[tex] \bar X = 69.8[/tex] the sample mean

[tex] n= 140[/tex] represent the sample size

[tex] s = 11.2[/tex] represent the standard deviation

Part a

And we want to test if the true mean is equal to 69.3 so then the system of hypothesis:

Null hypothesis: [tex] \mu = 69.3[/tex]

Alternative hypothesis: [tex]\mu \neq 69.3[/tex]

Part b: Find the statistic

The statistic is given by:

[tex] z= \frac{\bar X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

And replacing the info we got:

[tex] z = \frac{69.8- 69.3}{\frac{11.2}{\sqrt{140}}}= 0.528[/tex]

Answer:

-8.5

Step-by-step explanation:

-4x+8=42

-4x=42-8

-4x=34

x=34/-4

x=-8.5

Answer:

A =50.24 in ^2

Step-by-step explanation:

The diameter is 8 inches

The radius is 1/2 diameter

r = d/2 = 8/2 = 4

The area of the circle is given by

A = pi r^2

A = 3.14 (4)^2

A =50.24 in ^2

Answer:

C. 50.24 in²

Step-by-step explanation:

d= 8 in

r= 8/2= 4 in

Area= πr²= 3.14×4²= 50.24 in²

Answer:

[tex]2^{6}[/tex]

Step-by-step explanation:

[tex]2^3 \div 2^{-3}[/tex]

[tex]2^{3-(-3)}[/tex]

[tex]2^{3+3}[/tex]

[tex]2^{6}[/tex]

[tex]\displaystyle\bf\\AB=\sqrt{\Big(-6-(-2)\Big)^2+\Big(4-(-7)\Big)^2}\\\\AB=\sqrt{\Big(-6+2\Big)^2+\Big(4+7\Big)^2}\\\\AB=\sqrt{\Big(-4\Big)^2+\Big(11\Big)^2}\\\\AB=\sqrt{16+121}\\\\\boxed{\bf AB=\sqrt{137}}[/tex]

.

[tex]\displaystyle\bf\\BC=\sqrt{\Big(-2-(-6)\Big)^2+\Big(7-4\Big)^2}\\\\BC=\sqrt{\Big(-2+6\Big)^2+\Big(7-4\Big)^2}\\\\BC=\sqrt{\Big(4\Big)^2+\Big(3\Big)^2}\\\\BC=\sqrt{16+9}\\\\BC=\sqrt{25}\\\\\boxed{\bf BC=5}[/tex]

.

[tex]\displaystyle\bf\\CD=\sqrt{\Big(2-(-2)\Big)^2+\Big(4-7\Big)^2}\\\\CD=\sqrt{\Big(2+2\Big)^2+\Big(4-7\Big)^2}\\\\CD=\sqrt{\Big(4\Big)^2+\Big(-3\Big)^2}\\\\CD=\sqrt{16+9}\\\\CD=\sqrt{25}\\\\\boxed{\bf CD=5}[/tex]

.

[tex]\displaystyle\bf\\AD=\sqrt{\Big(2-(-2)\Big)^2+\Big(4-(-7)\Big)^2}\\\\AD=\sqrt{\Big(2+2\Big)^2+\Big(4+7\Big)^2}\\\\AD=\sqrt{\Big(4\Big)^2+\Big(11\Big)^2}\\\\AD=\sqrt{16+121}\\\\\boxed{\bf AD=\sqrt{137}}[/tex]

.

[tex]\displaystyle\bf\\P=AB+BC+CD+AD=\sqrt{137}+5+5+\sqrt{137}\\\\\boxed{\bf P=10+2\sqrt{137}}[/tex]

[tex]answer \\ \\ \frac{ \sqrt{5} }{2 \sqrt{a} } \\ please \: see \: the \: attached \: picture \: for \: full \: solution \\ hope \: it \: helps[/tex]

Answer:

The probability that exactly eight of them take more than 93.6 minutes is 5.6015 [tex]\times 10^{-6}[/tex] .

Step-by-step explanation:

We are given that it is known that times for service calls follow a normal distribution with a mean of 75 minutes and a standard deviation of 15 minutes.

A random sample of twelve service calls is taken.

So, firstly we will find the probability that service calls take more than 93.6 minutes.

Let X = times for service calls.

So, X ~ Normal([tex]\mu=75,\sigma^{2} =15^{2}[/tex])

The z-score probability distribution for the normal distribution is given by;

                              Z  =  [tex]\frac{X-\mu}{\sigma}[/tex]  ~ N(0,1)

where, [tex]\mu[/tex] = mean time = 75 minutes

           [tex]\sigma[/tex] = standard deviation = 15 minutes

Now, the probability that service calls take more than 93.6 minutes is given by = P(X > 93.6 minutes)

       P(X > 93.6 min) = P( [tex]\frac{X-\mu}{\sigma}[/tex] > [tex]\frac{93.6-75}{15}[/tex] ) = P(Z > 1.24) = 1 - P(Z [tex]\leq[/tex] 1.24)

                                                                = 1 - 0.8925 = 0.1075

The above probability is calculated by looking at the value of x = 1.24 in the z table which has an area of 0.8925.

Now, we will use the binomial distribution to find the probability that exactly eight of them take more than 93.6 minutes, that is;

[tex]P(Y = y) = \binom{n}{r}\times p^{r} \times (1-p)^{n-r} ; y = 0,1,2,3,.........[/tex]

where, n = number of trials (samples) taken = 12 service calls

            r = number of success = exactly 8

            p = probability of success which in our question is probability that

                   it takes more than 93.6 minutes, i.e. p = 0.1075.

Let Y = Number of service calls which takes more than 93.6 minutes

So, Y ~ Binom(n = 12, p = 0.1075)

Now, the probability that exactly eight of them take more than 93.6 minutes is given by = P(Y = 8)

               P(Y = 8)  =  [tex]\binom{12}{8}\times 0.1075^{8} \times (1-0.1075)^{12-8}[/tex]

                             =  [tex]495 \times 0.1075^{8} \times 0.8925^{4}[/tex]

                             =  5.6015 [tex]\times 10^{-6}[/tex] .

Answer:

  D.  x is all real numbers

Step-by-step explanation:

The graph only goes from -11 to +11 in the horizontal direction, but that domain is not a choice. Apparently, we're to assume the graph extends to infinity both to the left and the right.

The domain is the horizontal extent of the function, so is ...

  x is all real numbers

Answer:

a) Q1= 144.10

Median = 150

Q3=155.90

b) The 99 percentile would be:[tex]a=150 +2.33*8.75=170.39[/tex]

And represent a value who accumulate 99% of the values below

Step-by-step explanation:

Let X the random variable that represent the scores of a population, and for this case we know the distribution for X is given by:

[tex]X \sim N(150,8.75)[/tex]  

Where [tex]\mu=150[/tex] and [tex]\sigma=8.75[/tex]

Part a

Lets begin with the first quartile:

[tex]P(X>a)=0.75[/tex]   (a)

[tex]P(X<a)=0.25[/tex]   (b)

We can find the quantile in the normal standard distribution and we got z=-0.674.

And we can apply the z score formula and we got:

[tex]z=-0.674<\frac{a-150}{8.75}[/tex]

And if we solve for a we got

[tex]a=150 -0.674*8.75=144.10[/tex]

The median for this case is the mean [tex]Median =150[/tex]

For the third quartile we find the quantile who accumulate 0.75 of the area below and we got z=0.674 and we got:

[tex]a=150 +0.674*8.75=155.90[/tex]

Part b

We can find the quantile in the normal standard distribution who accumulate 0.99 of the area below and we got z=2.33.

And we can apply the z score formula and we got:

[tex]z=2.33<\frac{a-150}{8.75}[/tex]

And if we solve for a we got

[tex]a=150 +2.33*8.75=170.39[/tex]

And represent a value who accumulate 99% of the values below

Answer:

A 16 inches diameter will reward you with the largest slice of pizza.

Step-by-step explanation:

Let r be the radius and [tex]\theta[/tex] be the angle of a circle.

According with the graph, the area of the sector is given by

[tex]A=\frac{1}{2}r^2\theta[/tex]

The arc length of a circle with radius r  and angle  [tex]\theta[/tex] is r [tex]\theta[/tex]

The perimeter of the pizza slice is composed of two straight pieces, each of length r inches, and an arc of the circle which you know has length s = rθ inches. Thus the perimeter has length

The perimeter of the pizza slice is composed of two straight pieces, each of length r inches, and an arc of the circle which you know has length s = rθ inches.

Thus the perimeter has length

[tex]2r+r\theta=32 \:in[/tex]

We need to express the area as a function of one variable, to do this we use the above equation and we solve for [tex]\theta[/tex]

[tex]2r+r\theta=32\\\\r\theta=32-2r\\\\\theta=\frac{32-2r}{r}[/tex]

Next, we substitute this equation into the area equation

[tex]A=\frac{1}{2}r^2(\frac{32-2r}{r})\\\\A=\frac{1}{2}r(32-2r)\\\\A=16r-r^2[/tex]

The domain of the area is

[tex]0<r<12[/tex]

To find the diameter of pizza that will reward you with the largest slice you need to find the derivative of the area and set it equal to zero to find the critical points.

[tex]\frac{d}{dr} A=\frac{d}{dr}(16r-r^2)\\\\A'(r)=\frac{d}{dr}(16r)-\frac{d}{dr}(r^2)\\\\A'(r)=16-2r16-2r=0\\\\-2r=-16\\\\\frac{-2r}{-2}=\frac{-16}{-2}\\\\r=8[/tex]

To check if r=8 is a maximum we use the Second Derivative test

if [tex]f'(c)=0[/tex] and [tex]f''(c)<0[/tex] , then f(x) has a local maximum at x = c.

The second derivative is

[tex]\frac{d}{dr} A'(r)=\frac{d}{dr} (16-2r)\\\\A''(r)=-2[/tex]

Because [tex]A''(r)=-2 <0[/tex]  the largest slice is when r = 8 in.

The diameter of the pizza is given by

[tex]D=2r=2\cdot 8=16 \:in[/tex]

A 16 inches diameter will reward you with the largest slice of pizza.

[tex]x^2+14x+40=0\\x^2+14x+40+9-9=0\\x^2+14x+49=9\\(x+7)^2=9\\\\D=7\\E=9[/tex]

Answer:

x^2+14x+40=0\\x^2+14x+40+9-9=0\\x^2+14x+49=9\\(x+7)^2=9\\\\D=7\\E=9

Step-by-step explanation:

Answer: 0.66 ft

Step-by-step explanation:

Let assume that the initial position of the worker is x.

Given that the worker walks away with a constant speed of 2 ft/s. Therefore, dx/dt = 2

As the worker moves away, the rope makes a triangle, with width length x and the height length will be 30.

Using pythagorean theorem, the length of rope on this side of the pulley will be √(x² + 30²)

Also, the length of rope on the other side will be 60 - √(x² + 30²),

and the height h of the weight will be 30 - (60 - √(x² + 30²)) = √(x² + 30²) - 30

dh/dt = dx/dt × x/√(x² + 30²)

= 4x/√(x² + 30²)

dh/dt = 4x/√(x² + 30²)

If the worker moves 5ft away, then

dh/dt = (4×5)/√(5² + 30²)

dh/dt = 20/√(25 + 900)

dh/dt = 0.66 ft

Answer:

(a) The probability of waiting less than 12 minutes between successive speeders using the cumulative distribution function is 0.7981.

(b) The probability of waiting less than 12 minutes between successive speeders using the probability density function is 0.7981.

Step-by-step explanation:

The  cumulative distribution function of the random variable X, the waiting time, in hours, between successive speeders spotted by a radar unit is:

[tex]F(x)=\left \{ {{0;\ x<0} \atop {1-e^{-9x};\ x\geq 0}} \right.[/tex]

(a)

Compute the probability of waiting less than 12 minutes between successive speeders using the cumulative distribution function as follows:

[tex]12\ \text{minutes}=\frac{12}{60}=0.20\ \text{hours}[/tex]

The probability is:

[tex]P(X<0.20)=|F (x)|_{x=0.20}[/tex]

                  [tex]=(1-e^{-8x})|_{x=0.20}\\\\=1-e^{-8\times 0.20}\\\\=0.7981[/tex]

Thus, the probability of waiting less than 12 minutes between successive speeders using the cumulative distribution function is 0.7981.

(b)

The probability density function of X is:

[tex]f_{X}(x)=\frac{d F (x)}{dx}=\left \{ {{0;\ x<0} \atop {8e^{-8x};\ x\geq 0}} \right.[/tex]

Compute the probability of waiting less than 12 minutes between successive speeders using the probability density function as follows:

[tex]P(X<0.20)=\int\limits^{0.20}_{0} {8e^{-8x}} \, dx[/tex]

                  [tex]=8\times [\frac{-e^{-8x}}{8}]^{0.20}_{0}\\\\=[-e^{-8x}]^{0.20}_{0}\\\\=(-e^{-8\times 0.20})-(-e^{-8\times 0})\\\\=-0.2019+1\\\\=0.7981[/tex]

Thus, the probability of waiting less than 12 minutes between successive speeders using the probability density function is 0.7981.

Answer:

work is shown and pictured

Answer:

Step-by-step explanation:

Inventory turn over is the same as the inventory turn over ratio. Inventory turn over is defined simply as the ratio of the cost of goods that was sold (net sales) to the average inventory at the selling price.

Inventory turn over = Cost of goods/average inventory

Cost of goods sold = $50000

Average inventory = beginning of inventory + ending inventory/2

Average inventory = $16000+$20000/2

Average inventory = $36000/2

Average inventory = $18000

Inventory turn over = $50000/$18000

Inventory turn over= 2.78

Answer:

The question is not complete, as the table containing the data is missing, but I found a matching table that can be used to answer the question.

The Question is:

Which is the highest rated, of the four European cities under consideration, using the table.

The correct answer is: City A is the highest rated European city.

Step-by-step explanation:

The highest rated European city can be found by multiplying the factor and the importance of the factors, and summing up their final values. the cty with the highest number is the one with the highest rated city. Having this in mind, let us calculate the ratings for each of the cities as follows:

City A:

(70 × 20) + (80 × 20) + (100 × 20) + (80 × 10) + (90 × 10) + (65 × 10) + (70 × 10) = 1400 + 1600 + 2000 + 800 + 900 + 650 + 700 = 8050

City B:

(70 × 20) + (60 × 20) + (50 × 20) + (90 × 10) + (60 × 10) + (75 × 10) + (60 × 10) = 1400 + 1200 + 1000 + 900 + 600 + 750 + 600 = 6450

City C:

(60 × 20) + (90 × 20) + (75 × 20) + (65 × 10) + (50 × 10) + (85 × 10) + (65 × 10) = 1200 + 1800 + 1500 + 650 + 500 + 850 + 650 = 7150

City D:

(90 × 20) + (75 × 20) + (90 × 20) + (65 × 10) + (70 × 10) + (70 × 10) + (80 × 10)   = 1800 + 1500 + 1800 + 650 + 700 + 700 + 800 =7950

Therefore, from the ratings computed above, City A with a rating of 8050, is the highest rated, while City B with a rating of 6450, is the lowest rated.

Answer:

8/3

Step-by-step explanation:

6(x-2)=4

x-2=4/6

x= 8/3

Answer:

x = 8/3

Step-by-step explanation:

Use Distributive Property

6(x-2) = 4

6x -12 = 4

add 12 on both sides

6x = 16

Divide by 6

x = 8/3

In decimal form: 2.667

The first differences are 8, 14, 20.

The second differences are 6.

Half of 6 is 3, so the first term of the sequence is 3n^2.

If you subtract 3n^2 from the sequence you get 0,-1,-2,-3 which has the nth term of -n + 1.

Therefore your final answer will be 3n^2 - n + 1

Answer:

The difference between the games won and lost = 21 - 6 =15

Step-by-step explanation:

According to the question In a football season a team gets 3 points for a win, 1 point for a draw and 0 points for a loss.

A particular season a team played 34 games and lost 6 games . Finding the difference between game won and game lost simply means we have to know the number of game lost and game won.

The team played a total of 34 games.

Total games played = 34

Out of the 34 games played they lost 6 games. That means the remaining games is either win or draw. Therefore,

34 - 6 = 28 games was won or draw

Let

the number of games won = x

the number of game drew = y

3x + y = 70.............(i)

x  + y = 28................(ii)

x = 28 - y

insert the value of x in equation(i)

3(28 - y) + y = 70

84 - 3y + y = 70

84 - 70 = 3y -y

14 = 2y

divide both sides by 2

y = 14/2

y = 7

insert the value of y in equation(ii)

x + y = 28

x = 28 - 7

x = 21

The team won 21 games , drew 7 games and lost 6 games.

The difference between the games won and lost = 21 - 6 =15

Answer:

4 ( a+2)

Step-by-step explanation:

The average rate of change is

(f(a) - f(2))/(a-2)

f(a) = 4a^2 -8

f(2) = 4*2^2 -8 = 4*4 -8 = 16-8 = 8

(4a^2 - 8  - 8))/(a-2)

(4a^2 -16) / (a-2)

Factor the numerator

4( a^2 -4) / (a-2)

4( a-2)(a+2) / (a-2)

Cancel

4 ( a+2)

Answer:

y=-3x-2

Step-by-step explanation:

There is enough information to make a point-slope form equation that which we can convert into slope-intercept form.

Point-slope form is: [tex]y-y_1=m(x-x_1)[/tex]

We are given the slope of -3 and the point of (1,-5).

[tex]y-y_1=m(x-x_1)\rightarrow y+5=-3(x-1)[/tex]

Convert into Slope-Intercept Form:

[tex]y+5=-3(x-1)\\y+5-5=-3(x-1)-5\\\boxed{y=-3x-2}[/tex]

Answer:

4 pizza recipes

Step-by-step explanation:

It shows 4 Xs after the [tex]\frac{3}{4}[/tex] mark. So there are 4 recipes that use MORE than [tex]\frac{3}{4}[/tex] cups of cheese.

Answer:

4 cups of cheese

Step-by-step explanation:

More than 3/4 are (3+1) = 4 cups of cheese

Mark Wishing the Brainliest because he deserves it :)