help me please i am struggle with this

Answer:

11 + 10i

Step-by-step explanation:

Just treat i like any other variable, and combine like terms. Hope that helps!

Answer:

0.4444 = 44.44% probability that the sum of the two numbers is greater than 3 but less than 7.

Step-by-step explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

A number is selected at random from each of the sets {2,3,4} and {1, 3, 5}.

The possible values for the sum are:

2 + 1 = 3

2 + 3 = 5

2 + 5 = 7

3 + 1 = 4

3 + 3 = 6

3 + 5 = 8

4 + 1 = 5

4 + 3 = 7

4 + 5 = 9

Find the probability that the sum of the two numbers is greater than 3 but less than 7?

​4 of the 9 sums are greater than 3 but less than 7. So

[tex]p = \frac{4}{9} = 0.4444[/tex]

0.4444 = 44.44% probability that the sum of the two numbers is greater than 3 but less than 7.

The work is simply the dot product of the force and displacement (which I assume are given in Newtons and meters, respectively):

W = F • d

W = (5i + 3j - 2k) N • ((4i - j + 3k) m - (j + k) m)

W = (5i + 3j - 2k) • (4i - 2j + 2k) Nm

W = (20 - 6 - 4) Nm

W = 10 J

Answer:

The volume of the sphere is 2048 in³.

Step-by-step explanation:

The volume of a sphere is given by:

[tex] V = \frac{4}{3}\pi r^{3} [/tex]

Where:

r: is the radius = 8 in

Having the radius and by using 3 for π, the volume is:

[tex] V = \frac{4}{3}*3 (8 in)^{3} = 2048 in^{3} [/tex]

Therefore, the volume of the sphere is 2048 in³.

I hope it helps you!        

Answer:

y= (3/2)x - (5/2)

Step-by-step explanation:

Slope-intercept form is y=mx+b. So, 3x-2y=5 can be rearranged to slope-intercept form.

We need to isolate the y and get it by itself, so let's subtract the 3x from both sides.

-> -2y = 5 - 3x

Now we need to get rid of the -2 so that the y will be completely alone. So, divide the -2 from both sides of the equation.

-> y = (5/-2) (-3x/-2)

Now rearrange, and the negatives from the 3x and 2 cancel each other out and we are left with:

-> y = 3/2 x - 5/2

Answer:

a simple random sample (SRS).

Step-by-step explanation:

In Statistics, sampling can be defined as a process used to collect or select data (objects, observations, or individuals) from a larger statistical population using specific procedures.

There are various types of sampling used by researchers and these are;

1. Systematic sampling.

2. Convenience sampling.

3. Stratified sampling.

4. Cluster sampling.

5. Random sampling.

Random sampling also referred to as simple random sample (SRS) involves randomly selecting a subset of a larger population.

In this scenario, an elected government official randomly selected five schools at random from the 20 schools in her area and then interviews each of the teachers in those five schools, in order to get their opinions about voting. Thus, the government official is using a simple random sample (SRS).

Answer:

(a)[tex]0.15731[/tex]

(b)0.02275

Step-by-step explanation:

We are given that

Mean=0

Standard deviation=0.5 g

True weight of a sample=166 g

Let X denote the normal random variable  with mean =166+0=166

(a)

P(166.5<X<167.5)

=[tex]P(\frac{166.5-166}{0.5}<\frac{X-\mu}{\sigma}<\frac{167.5-166}{0.5})[/tex]

=[tex]P(1<Z<3)[/tex]

=[tex]P(Z<3)-P(Z<1)[/tex]

[tex]=0.99865-0.84134[/tex]

[tex]=0.15731[/tex]

(b)

[tex]P(X>167)=P(Z>\frac{167-166}{0.5})[/tex]

[tex]=P(Z>2)[/tex]

[tex]=1-P(Z<2)[/tex]

[tex]=1-0.97725[/tex]

[tex]=0.02275[/tex]

Answer:

90 cause 90 times 10 is 900 and 10% times 10 is 100%

Step-by-step explanation:

Answer: 90

Step-by-step explanation: 900 × .10 = 90

Answer:

2.-P = 0.38

3.-P [ Lb | Wt ]  =  0.788

Step-by-step explanation:

1.-Probability of choosing any box is, 1/3. So the probability of choosing the lucky box is 1/3

Let´s say the lucky box is the number 2 box  ( that consideration does not in any way change the problem generality)

Then we have

p₁ probability of choosing box  1 is 1/3   p₁´ Probability of win ticket is  0.12

p₂ probability of choosing box 2 is 1/3  p₂´Probability of win ticket is  0.90

p₃ probability of choosing box 3 is 1/3  p₃´ Probability of win ticket is  0.12

Then

P (of choosing a winning ticket is) = p₁*p₁´ + p₂*p₂´ +  p₃*p₃´

P  =  1/3*0.12 + 1/3*0.9 + 1/3*0.12

P  =  0.04 + 0.3 + 0.04

P = 0.38

3.- if I draw a winning ticket what is the probability it came from Lucky box

According to Bayes theorem

P [ Lb | Wt ]  =   P(Lb) * P[ Wt|Lb]/ P(Wt)

P(Lb) = 1/3  =  0.33333

P[Wt|Lb]  = 0.9

P(Wt) = 0.38

Then By substitution

P [ Lb | Wt ]  =  0.333 *  0.9 / 0.38

P [ Lb | Wt ]  =  0.788

Answer:

The point of intersection is [tex]( \frac{-1\pm\sqrt{5}}{2}, 0)[/tex]

Step-by-step explanation:

f(x) = 2x^2 + 3x - 3 and g(x) = - x^2

By equating them

2x^2 + 3x - 3 = -x^2

3x^2 + 3 x - 3 =  0

x^2 + x - 1 = 0

[tex]x^2 +x - 1 = 0 \\\\x = \frac{-1\pm\sqrt{5}}{2}[/tex]

9514 1404 393

Answer:

  see attached

Step-by-step explanation:

I find a graphing calculator to be the quickest way to create a graph of a system of equations. That result is attached.

__

If you want to graph the equations by hand, you need to know a couple of points on each line. When the equations are in slope-intercept form, the y-intercept is often a good place to start. Another point is usually easy to find based on the slope of the line, starting at the y-intercept.

__

Here, the equations are not in that form, but are in the form ax+by=c. In this form, it is often easy to find both the x- and y-intercepts and use those points to plot the line. Each intercept is found by setting the other variable to zero.

  x-intercept: c/a

  y-intercept: c/b

__

For the given lines, the first equation has intercepts (2, 0) and (0, 2). The line has a slope of -1 and makes an isosceles triangle with the axes in the first quadrant.

The second equation has intercepts (-1, 0) and (0, 2). This line has a slope of +2 and makes a triangle with the axes in the second quadrant.

Answer:

[tex]P(head) = 0.5600[/tex]

Step-by-step explanation:

Given

[tex]n = 500[/tex] -- number of toss

[tex]head = 280[/tex] --- outcomes of head

See comment

Required

Empirical probability of head

This is calculated as:

[tex]P(head) = \frac{n(head)}{n}[/tex]

[tex]P(head) = \frac{280}{500}[/tex]

[tex]P(head) = 0.5600[/tex]

Answer:

$4.50

Step-by-step explanation:

Use the mean formula: mean = sum of elements / number of elements

Let x represent the cost of the fifth book, and solve for x:

mean = sum of elements / number of elements

3.25 = (11.75 + x) / 5

16.25 = 11.75 + x

4.5 = x

So, the cost of the fifth book was $4.50

9514 1404 393

Answer:

  4.1

Step-by-step explanation:

x is the short leg of a right triangle with hypotenuse 8.8 cm and longer leg 7.8 cm. Its measure is found using the Pythagorean theorem:

  x^2 +7.8^2 = 8.8^2

  x^2 = 77.44 -60.84 = 16.60

  x = √16.6

  x ≈ 4.1

Answer:

The p-value of the test is 0.0066 < 0.05, which means that there is sufficient evidence at the 0.05 significance level to conclude that the mean salary differs from $39,385

Step-by-step explanation:

The average salary for public school teachers for a specific year was reported to be $39,385. Test if the mean salary differs from $39,385

At the null hypothesis, we test if the mean is of $39,385, that is:

[tex]H_0: \mu = 39385[/tex]

At the alternative hypothesis, we test if the mean differs from this, that is:

[tex]H_1: \mu \neq 39385[/tex]

The test statistic is:

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

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.

39385 is tested at the null hypothesis:

This means that [tex]\mu = 39385[/tex]

A random sample of 50 public school teachers in a particular state had a mean of $41,680, and the population standard deviation is $5975.

This means that [tex]n = 50, X = 41680, \sigma = 5975[/tex]

Value of the test statistic:

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

[tex]z = \frac{41680 - 39385}{\frac{5975}{\sqrt{50}}}[/tex]

[tex]z = 2.72[/tex]

P-value of the test and decision:

The p-value of the test is the probability that the sample mean differs from 39385 by at least 2295, which is P(|Z| > 2.72), which is 2 multiplied by the p-value of Z = -2.72.

Looking at the z-table, Z = -2.72 has a p-value of 0.0033

2*0.0033 = 0.0066

The p-value of the test is 0.0066 < 0.05, which means that there is sufficient evidence at the 0.05 significance level to conclude that the mean salary differs from $39,385

Answer:

A sample of 17 must be selected.

Step-by-step explanation:

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

[tex]\alpha = \frac{1 - 0.96}{2} = 0.02[/tex]

Now, we have to find z in the Z-table as such z has a p-value of [tex]1 - \alpha[/tex].

That is z with a pvalue of [tex]1 - 0.02 = 0.98[/tex], so Z = 2.054.

Now, find the margin of error M as such

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

The standard deviation from a previous study is 4 hours.

This means that [tex]\sigma = 4[/tex]

How large a sample must be selected if he wants to be 96% confident of finding whether the true mean differs from the sample mean by 2 hours?

A sample of n is required.

n is found for M = 2. So

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

[tex]2 = 2.054\frac{4}{\sqrt{n}}[/tex]

[tex]2\sqrt{n} = 2.054*4[/tex]

Simplifying both sides by 2:

[tex]\sqrt{n} = 2.054*2[/tex]

[tex](\sqrt{n})^2 = (2.054*2)^2[/tex]

[tex]n = 16.88[/tex]

Rounding up:

A sample of 17 must be selected.

Answer:

Step-by-step explanation:

two points are (-5,-2) and (-1,3)

slope=(3-(-2))/(-1-(-5))=(3+2)/(-1+5)=5/4

Answer:

3, 6, 11, 18, 27

Step-by-step explanation:

hope it helps

Divide total miles by speed:

360 / 50 = 7.2 hours

Answer:

D. <S, <R, <T

Step-by-step explanation:

Recall: On a triangle, the bigger an angle measure the longer the side opposite it and vice versa.

In ∆RST,

The longest side, SR = 22, is opposite to <T

Therefore, <T is the biggest angle.

Medium side, ST = 21, is opposite to <R, therefore,

<R is the medium angle measure

The smallest angle measure <S is opposite to the shortest side, RT.

Angels I'm order form the smallest to largest will be:

<S, <R, <T

Answer:

-15m^10 -38m8+57m^6+98m^4-30m^2

Answer:

jere is your answer i hope it will help u

Answer:

y=7x+2

Step-by-step explanation:

In this form of an equation (y=mx+b), m is the slope of the line and b is the y-intercept.

So, since the slope (m) is 7 and the y-intercept (b) is 2, the equation is:

y=7x+2

Answer:

f(-1) = 1

f(0) = 20

f(2) = 38

Step-by-step explanation:

f(-1) = 9×-1 + 10 = -9 + 10 = 1

f(0) = 9×0 + 20 = 0 + 20 = 20

f(2) = 9×2 + 20 = 18 + 20 = 38

we needed to use the second definition for f(0), because that is the same as saying x=0.

and that is in the domain of the second function definition ( x>=0).

Answer:

72 is 6% of 1200.

Step-by-step explanation:

Multiply 72 by 100.

72*100

Then divide the number by 6

(72*100)/6

You should get 1200.

So a Quadratic function,A quadratic function is one of the form f(x) = ax2 + bx + c, where a, b, and c are numbers with a not equal to zero

Answer:

5 Minutes

take 10 and add 12 for each minute until you pass 60