which of the following are solutions to the quadratic equation check all that apply x ^ 2 + 10x + 25 = 7​

Answer:

Step-by-step explanation:

Hello!

Be the variable of interest:

X: Number of weeks it takes a worker aged 55 plus to find a job

Sample average X[bar]= 22 weeks

Sample standard deviation S= 11.89 weeks

Sample size n= 40

a)

The point estimate of the population mean is the sample mean

X[bar]= 22 weeks

It takes on average 22 weeks for a worker aged 55 plus to find a job.

b)

To estimate the population mean using a confidence interval, assuming the variable has a normal distribution is

X[bar] ± [tex]t_{n_1; 1-\alpha /2}[/tex] * [tex]\frac{S}{\sqrt{n} }[/tex]

[tex]t_{n-1; 1-\alpha /2}= t_{39; 0.975}= 2.023[/tex]

The structure of the interval is "point estimate" ± "margin of error"

d= [tex]t_{n_1; 1-\alpha /2}[/tex] * [tex]\frac{S}{\sqrt{n} }[/tex]= 2.023*[tex](\frac{11.89}{\sqrt{40} })[/tex]= 3.803

c)

The interval can be calculated as:

[22  ±  3.803]

[18.197; 25.803]

Using s 95% confidence level, you'd expect the population mean of the time it takes a worker 55 plus to find a job will be within the interval [18.197; 25.803] weeks.

d)

Job Search Time (Weeks)

21 , 14, 51, 16, 17, 14, 16, 12, 48, 0, 27, 17, 32, 24, 12, 10, 52, 21, 26, 14, 13, 24, 19 , 28 , 26 , 26, 10, 21, 44, 36, 22, 39, 17, 17, 10, 19, 16, 22, 5, 22

To study the form of the distribution I've used the raw data to create a histogram of the distribution. See attachment.

As you can see in the histogram the distribution grows gradually and then it falls abruptly. The distribution is right skewed.

Answer:

465 hours

Step-by-step explanation:

Please see attached picture for full solution.

1. substitute the value of A with the surface area of the pond

2. ensure that the coefficient of e is 1.

3. ln both sides

4. bring power down (for left side)

5. ln e= 1

6. find time taken in days

7. change number of days to hours

Answer:

350 miles long.

Step-by-step explanation:

First, we analyze the breakdown of the journey

Let the total distance of the journey =x

Therefore:

10% of the total distance of the journey =35 miles

10% of x=35

0.1x=35

Divide both sides by 0.1

x-350 miles

Therefore, the journey was 350 miles long.

Answer:

The journey was 350 miles long

Step-by-step explanation:

The parameters given are;

Distance traveled by Abena alone = 40% and the last half

∴  Distance traveled by Abena alone = 40% + 50% = 90%

Distance Abena traveled with Saralyn = 35 miles = 100% - 90% = 10%

Hence 10% of Abena's journey = 35 miles

The total distance of Abena's journey therefore, is given as follows

10% = 35 miles

Total distance of Abena's journey = 100% of Abena's journey = 10 × 10%

10 × 10% = 10 × 35 miles = 350 miles

The total distance of Abena's journey = 350 miles.

Answer:

538

Step-by-step explanation:

l x w

7x39

12x20

5x5

538

Answer:

21 x^2

Step-by-step explanation:

12x^2+9x^2

Combine like terms

x^2(12+9)

x^2(21)

21 x^2

Answer:

  24

Step-by-step explanation:

Let t represent the volume of the tank in gallons. Then we have ...

  (1/8)t + 15 = (3/4)t . . . . . . . . . . . adding 15 gallons fills the tank to 3/4

  15 = (6/8 -1/8)t = (5/8)t . . . . . . . subtract 1/8t

  15(8/5) = (8/5)(5/8)t . . . . . . . . . multiply by 8/5 (the inverse of 5/8)

  24 = t

The tank holds 24 gallons.

Here is the full question .

We are interested in finding an estimator for [tex]Var (X_i )[/tex] and propose to use :

[tex]\hat {V} = \bar {X}_n (1- \bar {X} )_n[/tex]

Now; we are interested in the basis of [tex]\hat V[/tex]

Compute :

[tex]E \ \ [ \bar V] - Var (X_i) =[/tex]

Using this; find an unbiased estimator [tex][ \bar V][/tex] for [tex]p(1-p) \ if \ n \geq 2[/tex]

Write [tex]bar \ x{_n} \ for \ X_n[/tex]

Answer:

Step-by-step explanation:

[tex]\bar X_n = \dfrac{1}{n} {\sum ^n _ {i=1} } \\ \\ E(X_i) = - \dfrac{1}{n=1} \sum p \dfrac{1}{n}*np = \mathbf{p}[/tex]

[tex]V(\bar X_n) = V ( \dfrac{1}{n_{i=1} } \sum ^n \ X_i )} = \dfrac{1}{n^2} \sum ^n_{i=1} Var (X_i) \\ \\ = \dfrac{1}{n^2} \ \sum ^n _{i=1} p(1-p) \\ \\ = \dfrac{1}{n^2}*np(1-p) \\ \\ = \dfrac{p(1-p)}{n}[/tex]

[tex]E( \bar X^2 _ n) = Var (\bar X_n) + [E(\bar X_n)]^2 \\ \\ = \dfrac{p(1-p)}{n}+ p \\ \\ = p^2 + \dfrac{p(1-p)}{n} \\ \\ \\ \hat V = \bar X_n (1- \bar X_n ) = \bar X_n - \bar X_n ^2 \\ \\ E [ \hat V] = E [ \bar X_n - \bar X_n^2] \\ \\ = E[\bar X_n ] - E [\bar X^2_n] \\ \\ = p-(p^2 + \dfrac{p(1-p)}{n}) \\ \\ = p-p^2 -\dfrac{p(1-p)}{n}[/tex]

[tex]=p(1-p)[1-\dfrac{1}{n}] = p(1-p)\dfrac{n-1}{n}[/tex]

[tex]Bias \ (\bar V ) = E ( \hat V) - Var (X_i) \\ \\ = p(1-p) [1-\dfrac{1}{n}] - p(1-p) \\ \\ - \dfrac{p(1-p)}{n}[/tex]

Thus; we have:

[tex]E [\hat V] = p(1-p ) \dfrac{n-1}{n}[/tex]

[tex]E [\dfrac{n}{n-1} \ \ \bar V] = p(1 -p)[/tex]

[tex]E [\dfrac{n}{n-1} \ \ \bar X_n (1- \bar X_n )] = p (1-p)[/tex]

Therefore;

[tex]\hat V ' = \dfrac{n}{n-1} \bar X_n (1- \bar X_n)[/tex]

[tex]\mathbf{ \hat V ' = \dfrac{n \bar X_n (1- \bar X_n)} {n-1}}[/tex]

Answer:

The value of Chi-square test statistic for a hypothesis test of independence is 14.22.

Step-by-step explanation:

The data provided is for one day's output of Kortholt's from the Melodic Kortholt Company.

The formula to compute the chi-square test statistic for a hypothesis of independence is:

[tex]\chi^{2}=\sum {\frac{(O-E)^{2}}{E}}[/tex]

The formula to compute the expected frequencies (E) is:

[tex]E=\frac{\text{Row Total}\times \text{Column Total}}{N}[/tex]

Consider the Excel output attached.

Compute the value of Chi-square test statistic as follows:

[tex]\chi^{2}=\sum {\frac{(O-E)^{2}}{E}}[/tex]

    [tex]=1.333+2.222+4.000+6.667\\=14.222\\\approx 14.22[/tex]

Thus, the value of Chi-square test statistic for a hypothesis test of independence is 14.22.

Answer:

  (294π +448) cm³ ≈ 1371.6 cm³

Step-by-step explanation:

The half-cylinder at the right end has a radius of 7 cm, as does the one on top. Together, the total length of these half-cylinders is 8 cm + 4cm = 12 cm. That is equivalent in volume to a whole cylinder of radius 7 cm that is 6 cm long.

The cylinder volume is ...

  V = πr²h = π(7 cm)²(6 cm) = 294π cm³

__

The cuboid underlying the top half-cylinder has dimensions 4 cm by 8 cm by 14 cm (twice the radius). So, its volume is ...

  V = LWH = (4 cm)(8 cm)(14 cm) = 448 cm³

Then the total volume of the composite figure is ...

  (294π +448) cm³ ≈ 1371.6 cm³

Answer:

CD

Step-by-step explanation:

For all sides except CD, you do not need the distance formula, since they are vertical or horizontal, meaning that you can find their length simply through subtraction. However, with side CD, since it is diagonal, you need to form a right triangle with to solve its length. Hope this helps!

Answer:

x = -7.33        OR         x = [tex]\frac{-22}{3}[/tex]

y = 13

Step-by-step explanation:

→You can use the substitution method. First, make y by itself in (-2 + 2y = 24):

-2 + 2y = 24

2y = 26

y = 13

→Then, plug in 13 for y into the other equation:

3x + 2y = 4

3x + 2(13) = 4

3x + 26 = 4

3x = -22

x = -7.33        OR         x = [tex]\frac{-22}{3}[/tex]

The Answer is 1/4

Step-by-step explanation:

The required constant of variation for given data is k = 1/4

The correct option is (a)

In a direct variation, the product of two variables; in an inverse variation, the ratio of two variables, is called constant of variation

Formula:

k = [tex]\frac{n}{fg}[/tex]

Here we have given that n = 4, f = 2 and g = 8

Substitute the given values into above formula

k = [tex]\frac{4}{2(8)} =\frac{1}{4}[/tex]

The required constant of variation is 1/4

Therefore the correct option is (a)

This is the conclusion to the answer.

Learn more about constant of variation here-

https://brainly.com/question/6499629

#SPJ2

Answer: Length: 4, width: 6

Step-by-step explanation:

Let the length be x and width be y

Then x=2y-8 and xy=24

Substitute to get 2y-8 * y = 24, so 2y^2-8y=24 or y^2-4y=12, then solve to get y=6 or y=-2. Since width is positive y=6.

Substitute y=6 into xy=24 to get x=4.

Length: 4, width: 6

Hope that helped,

-sirswagger21

Answer:

[tex] y = \frac{4}{3} - 5[/tex]

Step-by-step explanation:

[tex] - 3y = 15 - 4x \\ - 3y = - 4x + 15 \\ \\ y = \frac{ - 4x + 15}{ - 3} \\ \\ y = \frac{ - 4}{ - 3} x + \frac{15}{ - 3} \\ \\ y = \frac{4}{3} x - 5 \\ which \: is \: in \: slope - intercept \: form.[/tex]

Step-by-step explanation:

I hope it's correct... Hope this is what you want

Answer:

D.) Converges; 256

Step-by-step explanation:

x0= 192

x1 = 48 = 192/4

x2 = 12 = 192/(4 x 4)

Therefore, this series can be written as:

[tex]x_n = \frac{192}{4^n}[/tex]

Applying limits at infinity:

[tex]\lim_{n \to \infty} x_n= \lim_{n \to \infty} (\frac{192}{4^n}) = \frac{192}{\infty}=0[/tex]

Since the terms of the series tend to zero, we can affirm that the series converges.

The sum of an infinite converging series is:

[tex]S=\frac{x_0}{1-r} \\S=\frac{192}{1-\frac{1}{4} }\\S=256[/tex]

Thus, the answer is D.) Converges; 256

Answer:

  184 square cm

Step-by-step explanation:

The ratio of areas is the square of the ratio of the scale factor. The larger triangle has an area of ...

  (15 cm²)(3.5²) = 183.75 cm²

The area of the similar triangle is about 184 cm².

Answer:

14 ft × 14 ft × 8.75 ft

Step-by-step explanation:

A garbage company is designing an open rectangular container that should have a volume of 1,715 cubic feet.

So we have the length of the container = "x" ft, the width of the container = "y" ft and the height of the container = "z" ft

Therefore the volume of the rectangular container would be:

x * y * z = 1715 ft³

z = 1715 / x * y

The cost of making the bottom of the container is $ 5 per square foot, that is:

5 * (x * y)

Now, area of ​​all sides of the container would be:

2 * (x * z + y * z) = 2 * z * (x + y)

We know that it has been given that the cost of making all the sides of the container is = $ 4 per square foot, so:

4 * (2 * z * (x + y)) = 8 * z * (x + y)

In total the costs would be:

5 * (x * y) + 8 * z * (x + y)

If we replace z, in the previous equation we have:

5 * (x * y) + 8 * (1715 / x * y) * (x + y)

solving, and we would have that the total cost would be:

C = 5 * (x * y) + 13720 / x + 13720 / y

Now we will find the derivative of C and make it equal to zero:

dC / dx = 0; dC / dy = 0

For dC / dx = 0:

dC / dx = 5 * y + 13720 * -1 / (y ^ 2) + 13720 * 0

0 = 5 * y - 13720 / y ^ 2

5 * y = 13720 / y ^ 2

y ^ 3 = 13720/5 = 2744

y = 14

For dC / dy = 0:

dC / dy = 5 * x + 13720 * 0 + 13720 * -1 / (x ^ 2)

0 = 5 * x - 13720 / x ^ 2

5 * x = 13720 / x ^ 2

x ^ 3 = 13720/5 = 2744

x = 14

now for z:

z = 1715 / (14 * 14)

z = 8.75

Therefore, the dimensions of the container should be 14 ft × 14 ft × 8.75 ft to minimize manufacturing cost.

Answer:

530.93 cm thats what i got at least

Answer:

A =530.66 cm^2

Step-by-step explanation:

The area of a circle is given by

A = pi r^2

The radius is given by r =13

A = (3.14) (13)^2

A =530.66 cm^2

Answer:

The dot product of vectors is the method used to "multiply" vecotrs since vectors aren't directly multiplieable

Step-by-step explanation:

Answer:

A meter is not part of the metric system. It's part of the U.S. customary system.

Answer: negative

Step-by-step explanation:

because –57 + 19= -38

and negative plus positive is negative

so the answer is negative

Hope this helps :)

Answer:

Negative

Compare the absolute values (how far the number is away from zero)

57 is bigger than 19

since 57 is negative and bigger than 19 when they add the sum will still be negative

Step-by-step explanation:

Answer:

Inductive reasoning

Step-by-step explanation:

I know that Molly is using inductive reasoning because she is collecting data from drawing and measuring the triangles to form a hypothesis. This hypothesis is whether or not there is a relationship between the largest angle and the largest side of a triangle.

Molly is using "Inductive Reasoning".

Inductive reasoning is a reasoning that is based on patterns you observe. If you observe a pattern in several tries, you can use inductive reasoning to decide the result of the next try, (although you have to be aware that the conclusion you reach this way may not be valid).

A conclusion you reach using inductive reasoning is called a "conjecture".  After measuring dozens of triangles, Molly has noticed a pattern, so she is ready to make a conjecture.

(It seems to me that a conjecture and a hypothesis are closely related.)

Now please arise from upon your knees.

Answer:

[tex]y=100[/tex]

Step-by-step explanation:

I don't know if by the 10 you mean the base is 10 or it's being logged with the y, but I'm assuming the base is 10. If that's not right, message me and I'll fix my answer. If,

[tex]log_an=x\\a^x=n[/tex]

Then,

[tex]log_1_0y=2\\10^2=y\\100=y[/tex]

Answer:

26.68% probability that exactly three will end up being replaced under warranty

Step-by-step explanation:

For each telephone under warranty, there are only two possible outcomes. Either they need to be replaced, or they do not need to be replaced. Each telephone is independent of other telephones. So we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of X happening.

30% must be replaced with new units

This means that [tex]p = 0.3[/tex]

If a company purchases ten of these telephones, what is the probability that exactly three will end up being replaced under warranty

This is [tex]P(X = 3)[/tex] when [tex]n = 10[/tex]. So

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 3) = C_{10,3}.(0.3)^{3}.(0.7)^{7} = 0.2668[/tex]

26.68% probability that exactly three will end up being replaced under warranty

Answer:

Dependent variable → bacteria cell increase or population

Independent variable → time variable

Step-by-step explanation:

An independent variable has direct effect on the dependent variable. The independent variable can stand on it own and it is not change by the other variable you are trying to measure. The independent variable have direct effect on the dependent variable.

A dependent variable is actually the variable being tested in an experiment. The dependent variable is actually dependent on the independent variable.

The dependent variable in this scenario is the bacteria cell increase or the bacteria cell multiplication.  The bacteria cell increase is dependent on the time . The time variable is the independent  variable as it can stand on it own .

Dependent variable → bacteria cell increase or population

Independent variable → time variable

Answer:

$4,000,000

Step-by-step explanation:

20,000*200=4,000,000

Answer:

Step-by-step explanation:

a)4a-6a                   d)2x+4y-10x

   =-2a.                     =-8-+4y

b)14-1-10

=3

c)2+8

=10

e)answer is 6 x raised to the power 3

f)7x raised to the power 2-5x-y

Last year- 8 lbs 3 ounces

Add 2 lbs and 4 ounces

Which is 10 lbs 7 ounces

10 lbs in onces is 160 ounces

Then you add the other 7 ounces so the final answer is 167 ounces

Tyson’s puppy weighs 167 ounces!

Good luck please mark me as braniliest!!!!!!

Answer:

Class width = 20

Approximate lower class limit of the first class = 110

Approximate Upper class limit of the first class = 119

Step-by-step Explanation:

The class width of the histogram attached below can be gotten by finding the difference between successive lower class limits.

Thus, class width = 130 - 110 = 20

The approximate lower class limit of the first class is the lowest score we have in the first class = 110

The approximate upper class limit of the first class is the closest highest score that fall within the first class and is below the lower limit of the second class. Thus approximate upper class limit of the first class = 129