Some Field Experience in the use of an Accelerated Method in Estimating 28-Day Strength of Concrete" considered regressing y =28-day standard-cured strength (psi) against x =accelerated strength (psi). Suppose the equation of the true regression line is y =1800 +1.3x.



a.What is the expected value of 28-day strength when accelerated strength= 2500? (2 marks)


b.By how much can we expect 28-day strength to change when accelerated strength increases by 1 psi? (4 marks)


c. Answer part (b) for an increase of 100 psi. (2 marks)


d. Answer part (b) for a decrease of 100 ps

Answers

Answer 1

Answer:

(a) 5,050 psi.(b) 5,051.3 psi.(c) 5,180 psi.(d) 4,920 psi.

Step-by-step explanation:

The given function is

[tex]y=1800+1.3x[/tex]

Where [tex]x[/tex] represents the accelerated strength in psi, and [tex]y[/tex] represents 28-day standard-cured strength in psi.

Part a is about finding the y-value for [tex]x=2500[/tex]

[tex]y=1800+1.3(2500)=1800+3250=5,050[/tex]

Therefore, the expected value of 28-day strength when accelerated strength is 2,500, is 5,050 psi.

Part b is about the y-value for [tex]x=2501[/tex]

[tex]y=1800+1.3(2501)=1800+3251.3=5,051.3[/tex]

Part c is about the y-value for [tex]x=2600[/tex]

[tex]y=1800+1.3(2600)=1800+3380=5,180[/tex]

Part d is about the y-value for [tex]x=2400[/tex]

[tex]y=1800+1.3(2400)=1800+3120=4,920[/tex]


Related Questions

if a cube measures 5.3 cm on each side and has a mass of 280 grams how much is its volume​

Answers

Answer:

8.1 g/cm

Step-by-step explanation:

Jessica bought the ingredients to make chicken soup, and wanted to make a double batch, which would be 18 cups of soup. A quick Google search told her that this was 259.9 cubic inches. She hoped the soup pot below would be big enough. The soup pot is 9 inches tall with a radius of 3.5 inches. What is the volume of the soup pot? Answer choices are rounded to the nearest tenth cubic inch. 169.6 cubic inches 890.6 cubic inches 197.9 cubic inches 346.4 cubic inches

Answers

Answer: 346.4 in^3

Step-by-step explanation:

The pot can be thinked as a cylinder:

The volume of a cylinder is equal to:

V = (pi*r^2)*h

where h is the height, r is the radius and pi = 3.1416

Here we have that: r = 3.5in, h = 9in.

Then the volume is:

V = 3.1416*(3.5in)^2*9in = 346.4in^3

The scores on one portion of a standardized test are approximately Normally distributed, N(572, 51). a. Use the 68-95-99.7 rule to estimate the range of scores that includes the middle 95% of these test scores. b. Use technology to estimate the range of scores that includes the middle 90% of these test scores.

Answers

Answer:

a) The range of scores that includes the middle 95% of these test scores is between 470 and 674.

b) The range of scores that includes the middle 90% of these test scores is between 488.1 and 655.9.

Step-by-step explanation:

68-95-99.7 rule:

The Empirical Rule states that, for a normally distributed random variable:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviation of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

Z-score:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this question:

Mean [tex]\mu = 572[/tex], standard deviation [tex]\sigma = 51[/tex]

a. Use the 68-95-99.7 rule to estimate the range of scores that includes the middle 95% of these test scores.

By the 68-95-99.7 rule, within 2 standard deviations of the mean.

572 - 2*51 = 470

572 + 2*51 = 674

The range of scores that includes the middle 95% of these test scores is between 470 and 674.

b. Use technology to estimate the range of scores that includes the middle 90% of these test scores.

Using the z-score formula.

Between these following percentiles:

50 - (90/2) = 5th percentile

50 + (90/2) = 95th percentile.

5th percentile.

X when Z has a pvalue of 0.05. So when X when Z = -1.645.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]-1.645 = \frac{X - 572}{51}[/tex]

[tex]X - 572 = -1.645*51[/tex]

[tex]X = 488.1[/tex]

95th percentile.

X when Z has a pvalue of 0.95. So when X when Z = 1.645.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]1.645 = \frac{X - 572}{51}[/tex]

[tex]X - 572 = 1.645*51[/tex]

[tex]X = 655.9[/tex]

The range of scores that includes the middle 90% of these test scores is between 488.1 and 655.9.

A 6-sided die is rolled three times. What is the probability of rolling a 4 each time?
A 0.00463
B. 0.99537
C 0.16667
D. 0.00231

Answers

Answer:

a

Step-by-step explanation:

math

Solve.
A European swallow flies about 12 meters in 1 second.
How many kilometers could it fly in 15 minutes?
It could fly |​

Answers

Answer:

It could fly 10,8 kilometers.

Step-by-step explanation:

The European swallow fly speed is 12 meters per second.

We have to calculate how many kilometers it could fly in 15 minutes.

This can be calculated using the equivalent factors for each of the units:

- 1 km is equivalent to 1,000 meters.

- 1 minute is equivalent to 60 seconds.

We know that the distance travelled by the fly is the product of the speed and the time, so we have:

[tex]D=v\cdot t\\\\\\D=12\,\dfrac{m}{s}\cdot15\, min\\\\\\D=12\,\dfrac{m}{s}\cdot(\dfrac{1\,km}{1,000\,m})\cdot15\, min\cdot (\dfrac{60\,s}{1\,min})\\\\\\D=\dfrac{12\cdot 15\cdot 60}{1,000}\,km=\dfrac{10,800}{1,000}\,km\\\\\\D=10,8 \,km[/tex]

Trust me,I will give braineist. I swear to god.

Answers

Answer:

= 1696m^3

Step-by-step explanation:

V = πr²h

= 3.14 x 6 x 6 x 15

= 3.14 x 540

= 1695.6 m^3

= 1696m^3

Identify two Pythagorean triples using the known triple 9, 40 , 41. *
Your answer

Answers

Step-by-step explanation:

[tex] {a}^{2} + {b}^{2} = {c}^{2} \\ {9}^{2} + {40}^{2} = {41}^{2} \\ 81 + 1600 = 1681 \\ 1681 = 1681[/tex]

A polynomial function has a root of -5 with multiplicity 3, a root of 1 with multiplicity 2, and a root of 3 with multiplicity 7. If the
function has a negative leading coefficient and is of even degree, which statement about the graph is true?
The graph of the function is positive on (-0, 5).
The graph of the function is negative on (-5, 3)
The graph of the function is positive on (-0, 1).
The graph of the function is negative on (3,co)
Mark this and return
Save and Exit
Sabem

Answers

Answer:

  The graph of the function is negative on (3, ∞)

Step-by-step explanation:

The function starts negative at the left side of the graph, crosses the x-axis at x = -5, touches the x-axis at x = 1, again crosses into negative values at x = 3.

The function is positive on the open intervals (-5, 1) and (1, 3). It is negative on the open intervals (-∞, -5) and (3, ∞). The latter description matches the last answer choice:

  the graph of the function is negative on (3, ∞).


A bookstore had 60 copies of a magazine. Yesterday, it sold 1/3 of them. Today, it sold 1/4 of what remained. How many copies does the bookstore have left?

Answers

Answer:

30

Step-by-step explanation:

1/3 of 60 is 20

40 would be left

1/4 of 40 is 10 so 30 would be left

The vertices of ΔDEF have coordinates D(–1, 2), E(3, 3), and F (2, –4).What are the coordinates of the vertices of r(90°, O)(ΔDEF)?

Answers

Answer:

D,E

Step-by-step explanation:

hope I helped

................................................

Answers

Answer:

V =108 ft^3

Step-by-step explanation:

The volume is found by

V = Bh  where B is the area of the base

B = the area of the trapezoid

B = 1/2 (b1+b2)*h of the trapezoid

B = 1/2(4+6)*4 = 1/2(10)*4 = 20

Now we can find the volume

V = 20* 9

V =108 ft^3

The picture shows a cement bag of weight Fg hanging from a rope which itself is supported by two other ropes attached to a ceiling. The latter two ropes make an angle θ1 and θ2 with the ceiling. Determine the tension in each rope. Use the angle addition identity to simplify your result: sin(α ± β) = sin α cos β ± cos α sin β

Answers

Answer:

[tex]T_1= \dfrac{F_gcos \theta_2}{sin (\theta_1+\theta_2)}[/tex]

Step-by-step explanation:

From the free body diagram attached  below; we will see that

T₃ = Fg   ------ (1)

Thus; as the system is in equilibrium, the net force in the x and y direction shows to be zero

Then;

[tex]\sum F_x= 0 \to T_2 Cos \theta _2 - T_1 cos \theta _1[/tex]

[tex]T_2 Cos \theta _2 = T_1 cos \theta _1 \ \ \ \ \ - - - (2)[/tex]

Also;

[tex]\sum F_y =0 \to T_2sin \theta_2+T_1sin \theta_1 - T_3 = 0[/tex]

[tex]T_3 = T_2sin \theta_2+T_1sin \theta_1[/tex]   ---- (3)

From equation (2):

[tex]T_2 = \dfrac{T_1cos \theta_1}{cos \theta_2}[/tex]

Replacing the above value for  T₂  into equation 3; we have

[tex]T_3 = \dfrac{T_1cos \theta_1}{cos \theta_2}sin \theta_2+T_1sin \theta_1[/tex]

[tex]T_3 cos \theta_2 = {T_1cos \theta_1}{}sin \theta_2+T_1sin \theta_1 cos \theta_2[/tex]

[tex]T_3 cos \theta_2 = T_1(cos \theta_1 sin \theta_2+sin \theta_1 cos \theta_2)[/tex]  ---- (4)

Using trigonometric identity Sin (A+B) = SIn A cos B + Cos A sin B

So ; equation 4 can now be:

[tex]T_3 cos \theta_2 = T_1sin(\theta _1 + \theta_2)[/tex]  --- (5)

replacing equation (1) into  equation (5) ; we have:

[tex]F_g}cos \theta_2 =T_1 sin (\theta_1+\theta_2)[/tex]

Hence; the tension in the string is:

[tex]T_1= \dfrac{F_gcos \theta_2}{sin (\theta_1+\theta_2)}[/tex]

1.] What is the probability of choosing a king
from a standard deck of playing cards?

Answers

Answer:

1/13

Step-by-step explanation:

there are 4 kings in a deck of 52 cards.

4/52 = 1/13

Which number line correctly shows 0.8 + 0.3?

Answers

Answer:

the second answer

Step-by-step explanation:

cause 0+0.8 is 0.8 and 0.8+0.3 is 1.1

Answer:

A

Step-by-step explanation:

Suppose the round-trip airfare between Philadelphia and Los Angeles a month before the departure date follows the normal probability distribution with a mean of $387.20 and a standard deviation of $68.50. What is the probability that a randomly selected airfare between these two cities will be between $325 and $425?

Answers

Answer:

52.74% probability that a randomly selected airfare between these two cities will be between $325 and $425

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this question, we have that:

[tex]\mu = 387.20, \sigma = 68.50[/tex]

What is the probability that a randomly selected airfare between these two cities will be between $325 and $425?

This is the pvalue of Z when X = 425 subtracted by the pvalue of Z when X = 325. So

X = 425

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{425 - 387.20}{68.50}[/tex]

[tex]Z = 0.55[/tex]

[tex]Z = 0.55[/tex] has a pvalue of 0.7088

X = 325

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{325 - 387.20}{68.50}[/tex]

[tex]Z = -0.91[/tex]

[tex]Z = -0.91[/tex] has a pvalue of 0.1814

0.7088 - 0.1814 = 0.5274

52.74% probability that a randomly selected airfare between these two cities will be between $325 and $425


You roll a six-sided number cube (die). What is the BEST answer for the probability that the number rolled is between 1 and 6, inclusive?
A) certain
B) unlikely
C) impossible
D) very likely

Answers

Answer: It is A certain.

Step-by-step explanation:

Because all the numbers on a six-sided cube is between 1 and 6 so it is certain or 100/100 that the number will land on a number between 1 and 6.

Daryl wishes to save money to provide for his retirement. He is now 30 years old and will be
retiring at age 64. Beginning one month from now, he will begin depositing a fixed amount into
a retirement savings account that will earn 12% compounded monthly. Then one year after
making his final deposit, he will withdraw $100,000 annually for 25 years. In addition, and after
he passes away (assuming he lives 25 years after retirement) he wishes to leave in the fund a sum
worth $1,000,000 to his nephew who is under his charge. The fund will continue to earn 12%
compounded monthly. How much should the monthly deposits be for his retirement plan?

Answers

Answer:

Step-by-step explanation:

Today's Age = 30

Retirement Age = 64

Total Monthly Deposits = ( 64 - 30 ) * 12 = 408

In case of 12% Compounded Monthly , Interest Rate per month = ( 12% / 12 ) = 1%

Effective Interest Rate per year = ( 1 + 0.12/12 )12 - 1 = 1.1268 - 1 = 0.1268 = 12.68%

Present value of Annual 25 Years withdrawal of $100,000 at time of Retirement = $100,000 * PVAF ( 12.68% , 25 )

= $100,000 * 7.4864

= $748,642.20

Present Value of Money for nephew at time of Retirement = $1,000,000 * PVF ( 12.68% , 25 )

= $1,000,000 * 0.050535

= $50,534.52

Now the Present Value of total Amount Required at time of Retirement = $748,642.20 + $50,534.52

= $799,176.70

Now the monthly deposit be X

= X * FVAF ( 408 , 1% ) = $799,176.70

= X * 5752.85 = $799,176.70

X = $138.918

Therefore Monthly Deposit = $138.92

What is the solution to the equation StartFraction m Over m + 4 EndFraction + StartFraction 4 Over 4 minus m EndFraction = StartFraction m squared Over m squared minus 16 EndFraction?

Answers

Answer: m = -2.

The given equation is: [tex]\frac{m}{m+4}+\frac{4}{4-m}=\frac{m^{2}}{m^{2}-16}[/tex].

The LCM of the denominators = [tex]m^{2}-16=(m+4)(m-4)[/tex].

We multiply both sides by LCM.

[tex]\left(m+4\right)\left(m-4\right)\left(\frac{m}{m+4}+\frac{4}{4-m}\right)=\left(m+4\right)\left(m-4\right)\cdot\frac{m^{2}}{m^{2}-16}[/tex]

[tex]m\left(m-4\right)-4\left(m+4\right)=m^{2}[/tex]

[tex]m^{2}-4m-4m-16=m^{2}[/tex]

[tex]8m=-16\\m=-2[/tex]

Learn more: https://brainly.com/question/13769924

Answer:

M=-2 B

Step-by-step explanation:

trust me i took the quiz

plzz help i hav a test after i need the answer quick plzz.

Answers

Answer:Oop

Step-by-step explanation:

Ramesh examined the pattern in the table. Powers of 7 Value 7 Superscript 4 2,401 7 Superscript 3 343 7 Superscript 2 49 7 Superscript 1 7 7 Superscript 0 1 7 Superscript negative 1 StartFraction 1 Over 7 EndFraction Ramesh says that based on the pattern 7 Superscript negative 5 = negative 16,807. Which statement explains whether Ramesh is correct? Ramesh is correct because 7 Superscript negative 5 is equivalent to Negative 7 times (negative 7) times (negative 7) times (negative 7) times (negative 7), which has the same value as Negative 16,807. Ramesh is correct because as the exponents decrease, the previous value is divided by 7, so 7 Superscript negative 5 = 1 divided by 7 divided by 7 divided by 7 divided by 7 divided by 7 = negative 16,807. Ramesh is not correct because 7 Superscript negative 5 is equivalent to StartFraction 1 Over 7 Superscript 5 EndFraction, which has the same value as StartFraction 1 Over 7 Superscript 4 EndFraction divided by 7 = StartFraction 1 Over 7 cubed EndFraction = StartFraction 1 Over 343 EndFraction. Ramesh is not correct because as the exponents decrease, the previous value is divided by 7, so 7 Superscript negative 5 = 1 divided by 7 divided by 7 divided by 7 divided by 7 divided by 7 = StartFraction 1 Over 16,807 EndFraction. NEED HELP NOW PLEASE I HAVE ONLY SEEN WRONG ANSWERS

Answers

Answer:

D

Step-by-step explanation:

Answer:

D.- Ramesh is not correct because as the exponents decrease, the previous value is divided by 7, so 7^-5 = 1 ÷ 7 ÷ 7 ÷ 7 ÷ 7 ÷ 7 = 1/16,807.

On circle OOO below, the measure of \stackrel{\LARGE{\frown}}{FJ} FJ ⌢ F, J, start superscript, \frown, end superscript is 84^\circ84 ∘ 84, degrees. The measure of \stackrel{\LARGE{\frown}}{GH} GH ⌢ G, H, start superscript, \frown, end superscript is 76^\circ76 ∘ 76, degrees. What is the measure of \angle HKJ∠HKJangle, H, K, J?

Answers

Answer:

100°

Step-by-step explanation:

The angle between chords is the average of the intersected arc angles.

∠FKJ = ½ (84° + 76°)

∠FKJ = 80°

∠HKJ is supplementary to ∠FKJ.

∠HKJ = 180° − 80°

∠HKJ = 100°

Find an equation for the nth term of the arithmetic sequence.
a16 = 21, a17 = -1

Answers

Answer:nth term=a1 - 27n + 27

Step-by-step explanation:

first term =a1

common difference=d=-1-21

d=-27

Using the formula

Tn=a1 + d x (n-1)

nth term=a1 + (-27)(n-1)

nth term=a1 - 27n + 27


The object below is a cubical lunch box having each edge as 10 cm.

​Find its surface area.


A
600 cm2
B
360 cm2
C
300 cm2
D
36 cm2

Answers

Answer:

B

Step-by-step explanation:

The total surface area of a cubical lunch box having each edge as 10 cm is 600 square centimeter. Therefore, option A is the correct answer.

What is surface area of a cube?

The surface area of the cube all six faces of the cube are made up of squares of the same dimensions then the total surface area of the cube will be the surface area of one face added six times to itself. The formula to find the surface area of a cube is 6a², where a is edge.

Given that, the cubical lunch box having each edge as 10 cm.

Here, surface area = 6×10²

= 600 square centimeter

Therefore, option A is the correct answer.

Learn more about the surface area of a cube here:

brainly.com/question/23273671.

#SPJ2

Please help worth 20 points!!

Answers

Answer:I would think u would

Step-by-step explanation:42,500×26

Answer:

1634.62$

Step-by-step explanation:

P=S/n

P=42500/26=1634.62

What is the value of 5x+3 when x = 4?

Answers

Answer:

Step-by-step explanation:

5(4)+ 3

20+3

23

The formula A=12(b+c)h. Write the equation in term of c?

Answers

Answer:

[tex]c = \frac{A}{12h} - b[/tex]

Step-by-step explanation:

Okay, so the goal is to isolate c on one side with all the other terms on the other side. So, let's start by dividing both sides with 12h. After we do that, we will be left with [tex]\frac{A}{12h} = b+c[/tex]. Now, we can subtract both sides by b, and we will be left with [tex]\frac{A}{12h} - b = c[/tex]. Yay! We've now isolated c and that is our final answer!

Hope this helped! :)

how many square feet of of outdoor carpet will we need for this hole?

Answers

Answer:

To convert the feet to square feet we have to multiply the length by the width. In which, we should get the answer as well.

Our length is 2ft, since it's a rectangle the other side is 2ft as well.

The width is 3ft, and the other half is 3ft.

So, basically to get the area of the hole, it'd be 3*2=

Which, it's 6sq ft.

Step-by-step explanation:The actual answer is 36. If I am wrong i am sorry ;3

The Senate in a certain state is comprised of 58 ​Republicans, 39 ​Democrats, and 3 Independents. How many committees can be formed if each committee must have 3 Republicans and 2 ​Democrats?

Answers

YuAnswer:

Step-by-step explanation:

I really don't know the answer sorry

Plz help ..............!!!!!

Answers

Answer:

1.8

is the median

Answer: 1.8

Step-by-step explanation: 1.8 is the median

Find the compound interest on GHS 50,200 invested at 13% p.a. compounded annually for 3 years ( to the nearest
GHS).
Select one:
A. GHS 19,578
B. GHS 69,778
O
C. GHS 72,433
D. GHS 22.233

Answers

Answer:

D

Step-by-step explanation:

First found amount yielded

A = P(1+r)^nt

P is amount deposited 50,200

r is interest rate 13% = 13/100 = 0.13

t = 3

A = 50,200(1+0.13)^3

A = 50,200(1,13)^3

A = 72,433.42939999998

A is approximately 72,433.43

interest = A - P = 72,433.43-50,200 = 22,233.43= 22,233 to the nearest GHS

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