CAn someone help me plsss

Answer : 169

Step-by-step explanation:

4(x+19) = 752

4x +76 = 752

4x = 752 - 76

x = 676/4

x=169

Hope this helps ;)

Please mark me the BRAINLIEST

Step-by-step explanation:

Given - In selecting a sulfur concrete for roadway construction in regions that experience heavy frost, it is important that the chosen concrete has a low value of thermal conductivity in order to minimize subsequent damage due to changing temperatures. Suppose two types of concrete, a graded aggregate and a no-fines aggregate, are being considered for a certain road. The table below summarizes data on thermal conductivity from an experiment carried out to compare the two types of concrete.

Type            ni                xi                  si

Graded       42           0.486            0.187

No-fines      42           0.359           0.158

To find - a. Formulate the above in terms of a hypothesis testing problem.

b. Give the test statistic and its reference distribution (under the null hypothesis).

c. Report the p-value of the test statistic and use it to assess the evidence that this sample provides on the scientific question of difference in mean conductivity of the two materials at the 5% level of significance.

Proof -

a.)

Hypothesis testing problem :

H0 : There is significant difference between mean conductivity for the graded concrete and mean conductivity for the no fines concrete.

H1 : There is no significant difference between mean conductivity for the graded concrete and mean conductivity for the no fines concrete.

b)

Test statistic :

[tex]Z = \frac{x_{1} - x_{2} }{\sqrt{\frac{s_{1} ^{2} }{n_{1}} + \frac{s_{2}^{2} }{n_{2}} } }[/tex]

[tex]Z = \frac{0.486 - 0.359 }{\sqrt{\frac{0.03496 }{42} + \frac{0.02496 }{42} } }[/tex]

[tex]Z = \frac{0.127 }{\sqrt{0.001468}}[/tex]

[tex]Z = \frac{0.127 }{0.0377}[/tex]

⇒Z(cal) = 3.3687

Z(tab) = 1.96

As Z (cal) > Z(tab)

So, we reject H0 at 5% Level of significance

p-value = 0.99962

Hence

There is significant difference in mean conductivity at the two materials.

Answer:

No, there is not sufficient evidence to support the claim that the bags are underfilled

Step-by-step explanation:

A manufacturer of potato chips would like to know whether its bag filling machine works correctly at the 434 gram setting.

This means that the null hypothesis is:

[tex]H_{0}: \mu = 434[/tex]

It is believed that the machine is underfilling the bags.

This means that the alternate hypothesis is:

[tex]H_{a}: \mu < 434[/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.

434 is tested at the null hypothesis:

This means that [tex]\mu = 434[/tex]

A 9 bag sample had a mean of 431 grams with a variance of 144.

This means that [tex]X = 431, n = 9, \sigma = \sqrt{144} = 12[/tex]

Value of the test-statistic:

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

[tex]z = \frac{431 - 434}{\frac{12}{\sqrt{9}}}[/tex]

[tex]z = -0.75[/tex]

P-value of the test:

The pvalue of the test is the pvalue of z = -0.75, which is 0.2266

0.2266 > 0.01, which means that there is not sufficient evidence to support the claim that the bags are underfilled.

Answer:

The number of required shelves is 5

You have to find the HCF of 45, 105, and 75.

Answer:

345 - 40% = 207$

Step-by-step explanation:

(345 - 30%) - 15% = 205.3 (Better deal)

Answer:

30% off and additional 15% at the register

Step-by-step explanation:

Deal 1

$345 × 40% = $138

$345 - $138 = $207

Deal 2

$205.30

Answer:

If the goal is to break the vases: 3/20 = 15.0% or 0.15

If the goal is to not break the vases: 17/20 = 85.0% or 0.85

9514 1404 393

Answer:

Step-by-step explanation:

These are all Law of Cosine problems. A generic expression for the length of side 'c' opposite angle C, which is defined by sides 'a' and 'b' is ...

  c² = a² +b² -2ab·cos(C)

The square root of this gives the side length:

  c = √(a² +b² -2ab·cos(C))

Rearranging the equation, we can obtain an expression for the angle C.

  C = arccos((a² +b² -c²)/(2ab))

These two formulas are used to solve the offered problems.

__

1) AC = √(13² +14² -2·13·14·cos(109°)) ≈ √483.506

  AC ≈ 22.0

__

2) BC = √(7² +10² -2·7·10·cos(123°)) ≈ √225.249

  BC ≈ 15.0

__

3) ∠B = arccos((24² +28² -14²)/(2·24·28)) = arccos(1164/1344)

  ∠B ≈ 30.0°

__

4) ∠B = arccos((6² +9² -14²)/(2·6·9)) = arccos(-79/108)

  ∠B ≈ 137.0°

Answer:I think 3 years

Step-by-step explanation:

sorry if im wrong

Answer:

I dont know I am sorry I really had to ask a question and i don't have enough points so sorry you can report me if you want but I really need some

Answer:

0.04845

Step-by-step explanation:

Probability that less than 7 but more than 4 bulbs from the sample are defective :

P(4 < X < 7) = P(x = 5) + P(x = 6)

Using the binomial probability formula :

P(x =x) = nCx * p^x * (1 - p)^(n - x)

From the question :

p = 0.2 ; 1 - p = 0.8 ; n = 11

P(x =5) = 11C5 * 0.2^5 * 0.8^6 = 0.03876

P(x = 6) = 11C6 * 0.2^6 * 0.8^5 = 0.00969

P(4 < X < 7) = P(x = 5) + P(x = 6)

P(4 < X < 7) = 0.03876 + 0.00969

P(4 < X < 7) = 0.04845

Answer:

c

Step-by-step explanation:

Answer:

54= 15 + J

Step-by-step explanation:

j= 39

Answer:

y = x/3 - 5

Step-by-step explanation:

Answer:

y = (1/3)x  - 5 .

Step-by-step explanation:

(-6 , -7) ; (3 ,-4)

Slope = [tex]\frac{y_{2}-y_{1}}{x_{2}-x_{1}}\\[/tex]

          [tex]=\frac{-4-[-7]}{3-[-6]}\\\\= \frac{-4 + 7}{3+6}\\\\= \frac{3}{9}\\\\=\frac{1}{3}[/tex]

m = 1/3   ; (3,-4)

y - y1 = m(x - x1)

[tex]y - [-4]=\frac{1}{3}(x-3)\\\\y + 4 = \frac{1}{3}x-3*\frac{1}{3}\\\\y + 4 = \frac{1}{3}x-1\\\\y =\frac{1}{3}x-1-4\\\\y = \frac{1}{3}x - 5[/tex]

Answer:

Darlene's dog weighs 10 pounds.

Step-by-step explanation: 5 x 10 = 50 and 50 + 10 = 60 pounds.

Hope this helps.

Answer:

Zane needs 240 strings for 5 harps.

Step-by-step explanation:

All you have to do is multiply

48 * 5 = 240

So, the answer is 240

Hope this helps! :)

Answer:

Yes, many times actually. I've aced tests because of brainly

Step-by-step explanation:

Answer:

90

Step-by-step explanation:

Answer:

(2/3)r=30

r=45cm

Step-by-step explanation:

When trying to find a fraction of something, multiply to get your answer:

(2/3) of r = (2/3)r

The blue ribbon can be represented by both 30cm and (2/3)r cm:

(2/3)r=30

2r=90

r=45cm

Answer: 4x^2

Step-by-step explanation: Multiply that by -1 to get -4x^2 and multiply by 7x to get 28x^3

Answer:

The number of milk chocolate pieces is between 115 and 120 pieces.

Step-by-step explanation:

Answer:

They are all correct.

Step-by-step explanation:

1.

1/2(b)(h)

1/2(4)(6)

1/2(24)

12

2. l x w

7 x 5

35

3. (b)(h)

(8)(4)

32

Answer:

$6510

Step-by-step explanation:

First thing that should come to mind is: What is 7% of $7000?

Well, if you don't know how to find a percent of something, this is the formula you use:

7000 x 0.07 = 490.

In the first year, they will receive 490 out of the 7000 they've invested.

7000 - 490 = 6510.

Therefore, the account balance at the end of the first year will be 6510.

The account balance at the end of first year will be equal to $6510.

What do you mean by percentage ?

Percentage is the relative value indicating one hundredth part of any quantity.

It is given that a retiree invests $7000 in a savings plan which pays 7% per year.  So , it meant that we need to calculate that what is the value 7% of $7000.

So , 7% of $7000 is :

= 7000 × [tex]\frac{7}{100}[/tex]

= $490

It is known that this amount is paid as per plan per year. So, to find out the account balance at the end of the first year , we need to subtract the invested amount to the amount per year at 7%.

So , the account balance at the end of first year will be :

= 7000 - 490

= $6510

Therefore , the account balance at the end of first year will be equal to $6510.

Learn more about percentage here :

brainly.com/question/22091903

#SPJ2

It's B because 2 equals 86 dgrees since its vertical angles

Answer:

x-30

Step-by-step explanation:

Answer: 5(x-2)=40     5x-10 = 40      5x=50    x=10  

Step-by-step explanation:

^

Answer: Area of the shape is 168 ft.

Step-by-step explanation: Split the shape into 2 shapes: A rectangle and a triangle.

Area of the rectangle shape is 144 and the area of the triangle is 24. Add them and you get 168.

Answer:

It can't be simplified or added together because one is multiplied by x and the other is not

Step-by-step explanation:

Answer:

5

Step-by-step explanation:

Answer:

B. 5(2x+5)

Step-by-step explanation:

Factor 5 out of 10x+25. and you get 5(2x+5)

Answer:

B. 5(2x + 5

Step-by-step explanation:

If you have any questions feel free to ask in the comments

Answer:

7x+14=0, 7x=-14, x= -2

Step-by-step explanation:

add like terms, then get x on one side, number on the other, then divide both sides by 7