When writing expressions for complex numbers, what does i represent?

Answer:

See attachment

Step-by-step explanation:

The solution is given in the image.

The graph of a feature f is the set of all factors in the plane of the form (x, f(x)). We can also outline the graph of f to be the graph of the equation y = f(x). So, the graph of a feature is a special case of the graph of an equation.

An axis is a line to the aspect or backside of a graph; it's far labeled to give an explanation for the graph's meaning and the devices of measurement. The x-axis, the horizontal line at the lowest of a graph, may be labeled to present facts about what the graph represents.

Learn more about graphs here: brainly.com/question/4025726

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Answer:

  $48.53

Step-by-step explanation:

The purchases can be written in equation form as ...

  4v +5f = 352.65

  2v +4f = 249.12

Doubling the second equation and subtracting the first gives ...

  2(2v +4f) -(4v +5f) = 2(249.12) -(352.65)

  3f = 145.59 . . . . simplify

  f = 48.53 . . . . . . divide by 3

The price of each football was $48.53.

Answer:

[tex]x^2-4x+4[/tex]

Step-by-step explanation:

[tex](x - 2)^2[/tex]

[tex](x - 2)(x - 2)[/tex]

[tex]x(x-2)-2(x-2)[/tex]

[tex]x^2-2x-2x+4[/tex]

[tex]x^2-4x+4[/tex]

Answer:

[tex]{x}^{2} - 4x + 4 \\ [/tex]

Step-by-step explanation:

[tex] {(x - 2)}^{2} \\ (x - 2)(x - 2) \\ x(x - 2) - 2(x - 2) \\ {x}^{2} - 2x - 2x + 4 \\ {x}^{2} - 4x + 4[/tex]

hope this helps you

Answer:

  -3i +-12j

Step-by-step explanation:

P2 -P1 = (-1-2, -6-6) = (-3, -12)

In terms of unit vectors i and j, this is -3i -12j.

Answer:

$900

Step-by-step explanation:

If she holds $500 and she is charged 15%; it means

The interest she pays per month is ;

$500 × 15/100 = $75

Then annually meaning for 12 months, she pays;

$75 × 12 = $900

Her annual interest on her current card is $900.

Therefore,

She will be taxed 15% if she holds $500, which means

The monthly interest she pays is;

$500 × 15/100 = $75

She then pays annually, which is for a full year;

$75 × 12 = $900

Hence, Her annual interest on her current card is $900.

To learn more about annual interest refer to:

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Answer:

q = 0.5 quarts of 100% antifreeze

Step-by-step explanation:

q = quarts of pure antifreeze

Set this up as a weighted combination of the mixtures.

(100%)(q) + (10%)(4) = (20%)(q + 4)

100q + 40 = 20(q + 4)

5q + 2 = q + 4

4q = 2

q = 0.5 quarts of 100% antifreeze

Answer:

  (-2, 1)

Step-by-step explanation:

For a relation consisting of (x, y) pairs to be a function, all of the x-values must be unique. In the given relation, points (-2, -3) and (-2, 1) have the same x-value. Removing either point will make the relation a function.

Of these, the only one listed among answer choices is (-2, 1).

Answer:

-2 , 1

Step-by-step explanation:

good luck love

Answer:

0

Step-by-step explanation:

1x=x

-x/1=-x

x-x=0

Answer:

Brainleist !

Step-by-step explanation:

x - x /1

x - x = nothing or 0

Answer:

(-3,2) is not a solution.

Step-by-step explanation:

The solution of a linear inequality in two variables like [tex]Ax + By > C[/tex] is an ordered pair [tex](x, y)[/tex] that produces a true statement when the values of x and y are substituted into the inequality.

To find if (-3,2) is a solution of [tex]7x+9y>-3[/tex], you must substitute this point into the inequality.

                                                 [tex]7\left(-3\right)+9\left(2\right)>-3\\\\-21+18>-3\\\\-3>-3[/tex]

Because -3 is not greater than -3, (-3,2) is not a solution.

Answer:

No

Step-by-step explanation:

Khan academy

Answer:

The correct option is (b) random.

Step-by-step explanation:

A simple random sample is a part of a statistical population in which every individual of the population has an equal probability of being selected.

Assigning each individual of the population a unique number and using a computer or random number generator for selection is a procedure to select a simple random sample.

In this case the researcher has a computer randomly generate several hundred numbers, and those numbers are used to select names from the list to form a sample.

The procedure indicates that the researcher used a simple random sampling technique to select the sample.

Thus, the correct option is (b).

Answer:

All college freshman is called Population and Right handed students are excluded is called sample from Population

Step-by-step explanation:

Explanation:-

Population:-  The total of the observations which we are concerned

given data all college freshman is called Population

Sample :-

A sample is a subset of a Population

Given data  all college freshman is called Population and Right handed students are excluded is called sample from Population

Answer:

108 pages

Step-by-step explanation:

Angelina read 30% of the book that contains 360 pages.

30% of 360 pages

"of" also means multiply, so we must multiply 30% and 360.

30% * 360

Convert 30% to a decimal. Divide 30 by 100, or move the decimal place 2 spots to the left.

30/100=0.30

or

30.0---> 3.0---> 0.30

Plug the decimal in for the percent.

0.30*360

Multiply the 2 numbers together

108

Angelina has read 108 pages so far.

Answer:

8 hours

Step-by-step explanation:

Solve with a proportion

[tex]\frac{12}{5}[/tex] = [tex]\frac{19.20}{x}[/tex]

Multiply 5 by 1.6 to get x

5 x 1.6 = 8

Answer:

I think it is 288.6 ft. Lol hope this helps

Step-by-step explanation:

d-Denis

e-Earl

d+e=42

e+8=d

e+8+e=42

2e+8=42

2e=34

e=17

d=17+8=25

Denis is 25 and Earl is 17

Answer

Earl is 17 years old.

Denis is 25 years old.

See? Easy!

Step-by-step explanation:

Answer:

102, 10, and, 3b

Step-by-step explanation:

Answer:

Height of this missing bar would be 1

Step-by-step explanation:

Since there is 1 and only 1 quantity between 80-99.

Answer:

1

There is 1 number that is between 80 and 99 which is 99 so there should be 1 bar.

Step-by-step explanation:

Answer:

30 mph

Step-by-step explanation:

Distance travelled=300 miles

Time travelled=10hours

At a constant rate,k

Let distance travelled=d

Time travelled=t

Then,

d=kt

300=k*10

300=10k

k=300/10

=30

k=30mph

30 miles per hour

30 MPH                                                                                       ............................................................................................................

Answer:

-7,9

Step-by-step explanation:

x-1=-8

x=-7

x-1=8

x=9

Answer:

Step-by-step explanation:

Hello!

Given the variables

Y: family spending

X₁: income of a family

X₂: family size

X₃: additions to savings of a family

And the regression output (see attachment)

The population model is Y= α + β₁X₁ + β₂X₂ + β₃X₃

a)

To write the estimated regression equation of the relationship between the variables you have to use the information given in the regression output. Under the column "coefficients", the value that corresponds to "intercept" is the estimation of the y-intercept (a), the value under X₁ corresponds to the estimation for the slop for the variable "income of the family" (b₁), under X₂ is the estimation of the slope for the variable "family size" (b₂) and under X₃ is the estimation for the slope corresponding to the variable "additions to savings" (b₃)

The estimated regression equation is:

^Y= a + b₁X₁ + b₂X₂ + b₃X₃

^Y= 0.0136 + 0.7992X₁ + 0.2280X₂ -0.5796X₃

b)

Using the SS information you can calculate the coefficient of determination as:

SStotal= SSReg+SSError= 45.9634+2.6218= 48.5852

[tex]R^2= \frac{SS_{Reg}}{SS_{Total}} = \frac{45.9634}{(48.5852)} = 0.946[/tex]

R²= 94.6%

This means that 94.6% of the variability of the average family spending is explained jointly by the family income, the family size and the addition to saving under the estimated model ^Y= 0.0136 + 0.7992X₁ + 0.2280X₂ -0.5796X₃

c)

The hypotheses are:

H₀: β₁= β₂= β₃= 0

H₁: At least one βi≠0 ∀ i=1, 2, 3

α: 0.05

The statistic for the multiple regression is

[tex]F=\frac{MS_{Reg}}{MS_{Error}} ~~F_{Df_{Reg};Df_{Error}}[/tex]

[tex]MS_{Reg}= \frac{SS_{reg}}{Df_{Reg}}= \frac{45.9634}{3} = 15.32[/tex]

[tex]MS_{Error}= \frac{SS_{Error}}{Df_{Error}} = \frac{2.6218}{11} = 0.238[/tex]

[tex]F_{H_0}= \frac{MS_{Reg}}{MS_{Error}}= \frac{15.32}{0.238}= 64.37[/tex]

p-value  < .00001

At a 5% significance level, there is enough evidence to reject the null hypothesis. This means that the family income, family size and the addition to savings modify jointly the average spending of families.

d.

Individual tests:

There are two possible statistics to test the significance of each independent variable: [tex]t= \frac{b_i-\beta_i }{S_{b_i}} ~~t_{n-3}[/tex] ∀ i= 1, 2, 3, or [tex]F=\frac{MS_{X_i}}{MS_{Error}} ~F_{Df_{X_i}; Df_{Error\\}}[/tex]

Since the output doesn't give us the information of the individual ANOVA, you have to use the t-test (Df: n-3= 12-3= 9) for these hypotheses. Using the p-value approach. the decision rule for the three hypothesis will be:

If p-value ≤ α ⇒ Reject null hypothesis.

If p-value > α ⇒ Do not reject the null hypothesis.

1)

H₀: β₁ = 0

H₁: β₁ ≠ 0

α: 0.05

[tex]t_{H_0}= \frac{b_1-\beta_1 }{Sb_1}= \frac{0.7992-0}{0.074}= 10.8[/tex]

p-value < .00001 ⇒ Decision is to reject the null hypothesis.

2)

H₀: β₂ = 0

H₁: β₂ ≠ 0

α: 0.05

[tex]t_{H_0}= \frac{b_2-\beta_2 }{Sb_2}= \frac{0.2280-0}{0.190}= 1.2[/tex]

p-value: 0.260773 ⇒ The decision is to not reject the null hypothesis.

3)

H₀: β₃ = 0

H₁: β₃ ≠ 0

α: 0.05

[tex]t_{H_0}= \frac{b_3-\beta_3 }{Sb_3}= \frac{-0.5796-0}{0.920}= -0.63[/tex]

p-value: 0.544355 ⇒ The decision is to not reject the null hypothesis.

So, at a 5% significance level, it seems that the three independent variables influence jointly the variation on the average spending of the families, but looking at them separately, only the income of the families seems to affect their spending habits significantly while the family size or their addition to savings don't seem to have major effect over their spending habits.

I hope this helps!

Answer:

We know that:

The original price was $515

and

It was $125 off

so we need to find the price of the sofa after the discount.

$515 - $125 = $390

The sale price of the sofa after the discount was $390

hope This helps and pls mark me brainliest if it did :)

Answer:

Step-by-step explanation:

it is -12 because -6 plus -6 is also like 6 plus 6

and then you have to add the negative Sign.

pls brainliest me

-6 - 6 = - 12

Happy to help! Please mark as the brainliest!

Answer:

answer is 2/3

Step-by-step explanation:

probability it is an eclair is 1/15=3/(3+2x+6+x)= 1/(x+3)

so x+3=15 and then x = 12

so the probability it is a humbug is (2*12+6)/(3*12+9) = 30/45 = 2/3

Answer:

a) The probability that fewer than five of them have type o negative blood is 0.1275

b) The probability that fewer than five of them have type o negative blood is 0.9933

c) 0.2708 probability of no donors with type o negative blood. This probability is higher than 0.05, so it would not be unusual having none of the donors with type o negative blood.

Step-by-step explanation:

For each person, there are only two possible outcomes. Either they have type o negative blood, or they do not. The probability of a person having type o negative blood is independent of any other person. 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.

7% of U.S. residents have type o negative blood.

This means that [tex]p = 0.07[/tex]

18 donors.

This means that [tex]n = 18[/tex]

(a) What is the probability that three or more of them have type o negative blood?

Either less than three have, or at least three do. The sum of the probabilities of these events is 1. So

[tex]P(X < 3) + P(X \geq 3) = 1[/tex]

We want [tex]P(X \geq 3)[/tex]

So

[tex]P(X \geq 3) = 1 - P(X < 3)[/tex]

In which

[tex]P(X < 3) = P(X = 0) + P(X = 1) + P(X = 2)[/tex]

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

[tex]P(X = 0) = C_{18,0}.(0.07)^{0}.(0.93)^{18} = 0.2708[/tex]

[tex]P(X = 1) = C_{18,1}.(0.07)^{1}.(0.93)^{17} = 0.3669[/tex]

[tex]P(X = 2) = C_{18,2}.(0.07)^{2}.(0.93)^{16} = 0.2348[/tex]

[tex]P(X < 3) = P(X = 0) + P(X = 1) + P(X = 2) = 0.2708 + 0.3669 + 0.2348 = 0.8725[/tex]

[tex]P(X \geq 3) = 1 - P(X < 3) = 1 - 0.8725 = 0.1275[/tex]

The probability that fewer than five of them have type o negative blood is 0.1275

(b) What is the probability that fewer than five of them have type o negative blood?

[tex]P(X < 5) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4)[/tex]

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

[tex]P(X = 0) = C_{18,0}.(0.07)^{0}.(0.93)^{18} = 0.2708[/tex]

[tex]P(X = 1) = C_{18,1}.(0.07)^{1}.(0.93)^{17} = 0.3669[/tex]

[tex]P(X = 2) = C_{18,2}.(0.07)^{2}.(0.93)^{16} = 0.2348[/tex]

[tex]P(X = 3) = C_{18,3}.(0.07)^{3}.(0.93)^{15} = 0.0942[/tex]

[tex]P(X = 4) = C_{18,4}.(0.07)^{4}.(0.93)^{14} = 0.0266[/tex]

[tex]P(X < 5) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) = 0.2708 + 0.3669 + 0.2348 + 0.0942 + 0.0266 = 0.9933[/tex]

The probability that fewer than five of them have type o negative blood is 0.9933.

c) Would it be unusual f none of the donors had type o negative blood?

[tex]P(X = 0) = C_{18,0}.(0.07)^{0}.(0.93)^{18} = 0.2708[/tex]

0.2708 probability of no donors with type o negative blood. This probability is higher than 0.05, so it would not be unusual having none of the donors with type o negative blood.

Answer:

Center line = 46

UCL = 46.84852

LCL = 45.15148

Step-by-step explanation:

Given:

Standard deviation = 0.8

Mean, u = 46

Sample size, n= 8

First calculate the estimated standard deviation:

[tex]s = \frac{\sigma}{\sqrt{n}} = \frac{0.8}{\sqrt{8}} = 0.282843[/tex]

a) The center line, X', would be the average across all components. Here the average across all 960 bottles is 46

Therefore,

[tex] X' = 46 [/tex]

b) The upper control limit, UCL:

UCL = u + 3s

= 46 + 3(0.28284)

= 46 + 0.84852

= 46.84852

c) The upper control limit, LCL:

LCL = u + 3s

= 46 - 3(0.28284)

= 46 - 0.84853

= 45.15148

Answer:

10

-5

Step-by-step explanation:

5 - -5

Subtracting a negative is like adding

5+5 = 10

-9 - -4

-9+4

-5

Answer:

Step-by-step explanation:

5+5 = 10

-9+4 = -5

Answer:

Step-by-step explanation:

Corresponding net sales before 1 month and after 1 month form matched pairs.

The data for the test are the differences between the net sales before and after 1 month.

μd = the​ net sales before 1 month minus the​ net sales after 1 month.

Before after diff

57.1 63.5 - 6.4

94.6 101.8 - 7.2

49.2 57.8 - 8.6

77.4 81.2 - 3.8

43.2 41.9 1.3

Sample mean, xd

= (- 6.4 - 7.2 - 8.6 - 3.8 + 1.3)/5 = - 4.94

xd = - 4.94

Standard deviation = √(summation(x - mean)²/n

n = 5

Summation(x - mean)² = (- 6.4 + 4.94)^2 + (- 7.2 + 4.94)^2 + (- 8.6 + 4.94)^2+ (- 3.8 + 4.94)^2 + (1.3 + 4.94)^2 = 60.872

Standard deviation = √(60.872/5

sd = 3.49

For the null hypothesis

H0: μd ≥ 0

For the alternative hypothesis

H1: μd < 0

The distribution is a students t. Therefore, degree of freedom, df = n - 1 = 5 - 1 = 4

2) The formula for determining the test statistic is

t = (xd - μd)/(sd/√n)

t = (- 4.94 - 0)/(3.49/√5)

t = - 3.17

We would determine the probability value by using the t test calculator.

p = 0.017

Since alpha, 0.05 > than the p value, 0.017, then we would reject the null hypothesis. Therefore, at 5% significance level, the data indicate that the average net sales improved.

Answer:

5

Step-by-step explanation:

3(14+x) = 57

42 +3x = 57

3x = 15

x = 5