Solve the system of equations 2x-4y=-2 and -x+8y=-23 by combining the equations.

Answer:2.25

Step-by-step explanation:

If the length of the road is 9 miles long and Mai ran 1/4 of the length of her road. Mai ran 2.25 miles.

It is defined as the operation in which we do the addition of numbers, subtraction, multiplication, and division. It has basic four operators that are +, -, ×, and ÷.

We'll apply division by Splitting into equal halves or groups, the division may be used to decide how to distribute a dish of cookies evenly among a group.

It is given that,

Length of road = 9 miles

From the condition,

Mai ran 1/4 of the length of her road

Mai ran =  1/4 × length of her road

Mai ran =  1/4 × 9

Mai ran =  2.25 miles.

Thus, if the length of the road is 9 miles long and Mai ran 1/4 of the length of her road. Mai ran 2.25 miles.

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Complete Question

A psychologist has designed an index to measure the social perceptiveness of elementary school children. The index is based on ratings of a child's responses to questions about a set of photographs showing different social situations. A random sample of 16 elementary school children was chosen, and their index measurements were recorded. Assume that the index measure in the population is normally distributed. The 95% confidence interval created from this data is (56.29, 65.09). This interval indicates:__________.Choose one or more:

a. The average index of elementary school children must be 60.69.

b. The standard deviation of the sample is about 10% smaller than the population standard deviation.

c. That if we take many samples from this population 95% of them will have a sample mean between 56.29 and 65.09.

d. 95% of all elementary school children in this district have indices between 56.29 and 65.09.

e. 4.40 is 95% of the true average of the index for all elementary school children.

f. We are 95% confident that the average index for all elementary school children is between 56.29 and 65.09.

Answer:

The correct option is  a and  f

Step-by-step explanation:

From the question we are told that

    The sample size is  n =  16

     The 95% confidence interval is  (56.29, 65.09)

Generally the sample mean(average index of elementary school children) is mathematically represented as

     [tex]\= x  =  \frac{65.09 + 56.29}{2}[/tex]

=>  [tex]\= x  =  60.69 [/tex]

Answer:

Step-by-step explanation:

add all internal angles

∠H + ∠I + ∠J = 180

where:

∠H = 3x - 2

∠I = 4x - 9

∠J = 3x - 9

plugin the values into the ∠H + ∠I + ∠J = 180 formula:

equation: 3x - 2 + 4x - 9 + 3x - 9 = 180

combine similar terms: 3x + 3x + 4x = 180 + 2 + 9 + 9

simplify: 10x = 200

divide 10 both sides: x = 20

Answer:

He enlarged the photo by 4.4 times than the original size.

Step-by-step explanation:

22/5=4.4

4.4*4=17.6

4.4*5=22

Answer:

It'll take 7.2 hours

Step-by-step explanation:

(5/3)in       12in

---------  x  --------

 1 hr          x hr

Cross multiply and you get

(5/3)x = 12

Then you divide 12 by (5/3) and you get that x = 7.2 hrs

Answer:

7.2 hours

Step-by-step explanation:

1 2/3 inches per hour = 5/3 inches per hour

12 inches = 36/3 inches

(36/3) / (5/3)

(36/3) x (3/5)

108/15

7.2 hours

Answer:

A. z = -2.4736

Step-by-step explanation:

n1 = 25

n2 = 25

x1 = 5500

x2 = 5850

Sd1= 550

Sd2 = 445

Null hypothesis

μ1 - μ2 = 0

Alternate

μ1 - μ2 != 0

Pooled variance = ((25-1)*550²)+((25-1)*445²)/25+25-2

= 7260000+4752600/48

= 250262.5

Pooled sd = √250262.5

= 500.26243

Test statistic

Z =

5500-5850+10/500.26243*√1/25+1/25

= -2.47357 approximately

-2.4736

Answer:

.65c

Step-by-step explanation:

2.60/4 equals .65

Answer:

.65

Step-by-step explanation:

2.06 divided by 4=.65

Hope this helped!

Answer:

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

Step-by-step explanation:

Slope Formula: [tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]

Simply plug in 2 coordinates into the slope formula to find slope m:

[tex]m=\frac{-4-(-1)}{5-1}[/tex]

[tex]m=\frac{-4+1}{4}[/tex]

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

Answer:

Two negatives = positive (17)

Step-by-step explanation:

Answer:

Today: Wednesday, 14 October 2020

Hour: 12.58 WIB

______________________________

-68 divinded (-4) is 17

Answer:

the answer is 1/2 because of the multiple of 3

What happened when the stock decreased by $123?

Answer:

2,5 then 17 20 then keep adding 15 for x and y

Answer:

x^2 - 4x + 4 = 0

x = 2

Step-by-step explanation:

(x - 2)(x - 2) = 0

x^2 - 2x - 2x + 4 = 0

x^2 - 4x + 4 = 0

The equation is:

x^2 - 4x + 4 = 0

It is a quadratic equation because of the x^2 term.

Now we solve it by factoring.

x^2 - 4x + 4 = 0

(x - 2)(x - 2) = 0

x - 2 = 0 or x - 2 = 0

x = 2 or x = 2

The only solution is x = 2.

Answer:

A

Step-by-step explanation:

Answer:

yes your answer it right.... brainliest plsss

Answer:

[tex](x + y) {}^{2} \\ = x {}^{2} + 2xy + y {}^{2} \\ = x {}^{2} + y {}^{2} + 2xy \\ = 23 + 2 \times 6 \\ = 23 + 12 \\ = 35 \\ \\ therefore \: the \: value \: \\ of \: (x + y) {}^{2} is \: 35.[/tex]

Thank you ☺️

Answer:

c

Step-by-step explanation:

The dots cannot intersect

Answer:

15,840?

Step-by-step explanation:

if f=5280m and m=3 then 5280x3= 15,840

Good luck!

Answer:

5/27

Step-by-step explanation:

Answer:i think its 3.25 miles

Step-by-step explanation:

Answer:

5.2

Step-by-step explanation:

13÷2.5=5.2

Is it a computer keyboard?

Answer:

False

Step-by-step explanation:

Decimals such as 1.2, 4.95, 2.28914 are all rational numbers.

If it doesnt end then its irrational, such as pi. but we know the exact amount of the numbers above therefore its rational. Also it can be put in fraction form which is another way to determine if rational or not.

5 3/8

Hi there !

1 1/2 + 3 7/8 =

= (1×2+1)/2 + (3×8+7)/8

= ⁴⁾3/2 + 31/8

= 12/8 + 31/8

= (12 + 31)/8

= 43/8

= 5 3/8

Good luck !

You haven't finished the question.

You need to finish the question before it can be answered.

Answer:

(a) 31101

(b) $5.65

(c) $113.38

Step-by-step explanation:

The complete question is:

A regional automobile dealership sent out fliers to prospective customers indicating that they had already won one of three different prizes: an automobile valued at $20,000, a $125 gas card, or a $5 shopping card. To claim his or her prize, a prospective print on the back of the flier listed the probabilities of winning. The chance of winning the car was 1 out of 31,101, the chance of winning the gas card was 1 out of 31,101, and the chance of winning the shopping card was 31, 099 out of 31,101.

Solution:

The information provided is as follows:

[tex]P(\text{Car})=\frac{1}{31101}\\\\P(\text{Gas Card})=\frac{1}{31101}\\\\P(\text{Shopping Card})=\frac{31099}{31101}[/tex]

(a)

The number of fliers the automobile dealership sent​ out is, n = 31,101.

This is because the probability of winning any of the three prize is out of 31,101.

(b)

Compute the expected value of the prize won by a prospective customer receiving a​ flier as follows:

[tex]E(X)=\sum x\times P(X=x)[/tex]

         [tex]=[20000\times \frac{1}{31101}]+[125\times \frac{1}{31101}]+[5\times \frac{31099}{31101}]\\\\=0.6431+0.0040+4.9997\\\\=5.6468\\\\\approx 5.65[/tex]

Thus, the expected value of the prize won by a prospective customer receiving a​ flier is $5.65.

(c)

Compute the standard deviation of the prize won by a prospective customer receiving a​ flier as follows:

[tex]SD(X)=\sqrt{V(X)}=\sqrt{E(X^{2}-(E(X))^{2}}[/tex]

           [tex]=\sqrt{[(20000)^{2}\times \frac{1}{31101}+(125)^{2}\times \frac{1}{31101}+(5)^{2}\times \frac{31099}{31101}]-(5.65)^{2}}\\\\=\sqrt{12854.9011}\\\\=113.37947\\\\\approx 113.38[/tex]

Thus, the standard deviation of the prize won by a prospective customer receiving a​ flier is $113.38.

Answer:

Money = (1500)e^(0.06t)

t = num of months

Money = Money at end of that tiem period

Answer:

Sienna

Step-by-step explanation:

Answer:

The temperature inside the freezer dropped 36°C.

Step-by-step explanation:

You need to subtract the new temperature from the old temperature to get the difference. That's a pretty cool freezer! (Pun intended!)

I hope this helps!

Answer:

Sample Response: The third DJ had (3r)/2 songs. Multiply r by 3 because the second DJ had 3 times as many as the first. Then divide that number by 2 because the third DJ has half as many.

DJ can arrange 88,55 times the first four songs on the playlist.

Permutation and combination are ways to arrange values in a set. In permutation the order of arrangement matters, but in combination the order of arrangement does not matter,

Given that,

DJ prepares a playlist of 23 songs.

Since, DJ arranges the first four songs on the playlist,

The ways to arrange the song on the playlist,

= [tex]^{23}C_4[/tex]

= 23 ! / (4! x (23 - 4)! )

= 23 ! / (4! x 19!)

= (23 x 22 x 21 x 20 x 19!) / (4 x 3 x 2 x 1  x 19!)

= 23 x 11 x 7 x 5

= 8855

There are 8,855 ways to arrange first 4 songs.

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