A civil engineer is analyzing the compressive strength of concrete. Compressive strength is normally distributed with A random sample of 12 sample specimens has a mean compressive strength of psi. Round your answers to 1 decimal place. (a) Calculate the 95% two-sided confidence interval on the true mean compressive strength of concrete. Enter your answer; 95% confidence interval, lower bound Enter your answer; 95% confidence interval, upper bound (b) Calculate the 99% two-sided confidence interval on the true mean compressive strength of concrete.
Answer:
95%: (3278.354 ; 3270.083)
99% : (3221.646 ; 3278.354)
Step-by-step explanation:
Given :
Sample size, n = 12
Mean, xbar = 3250
Sample standard deviation = √1000
The 95% confidence interval :
Mean ± Margin of error
Margin of Error = Tcritical * s/√n
Tcritical at 0.05, df=12-1 = 11 ;
Tcritical at 95% = 2.20
Hence,
Margin of Error = (2.20 * √1000/√12) = 20.083
Confidence interval : 3250 ± 20.083
Lower boundary = 3250 - 20.083 = 3229.917
Upper boundary = 3250 + 20.083 = 3270.083
2.)
The 99% confidence interval :
Mean ± Margin of error
Margin of Error = Tcritical * s/√n
Tcritical at 0.01, df=12-1 = 11 ;
Tcritical at 99% = 3.106
Hence,
Margin of Error = (3.106 * √1000/√12) = 28.354
Confidence interval : 3250 ± 28.354
Lower boundary = 3250 - 28.354 = 3221.646
Upper boundary = 3250 + 28.354 = 3278.354
Plz get me the correct answer or u will be reported. 15 points for correct answer. Thx.
Answer:
D
Step-by-step explanation:
correct answer, thanks for 15 pts
Answer:
Option D is correct
Step-by-step explanation:
Hope it is helpful....
Find the slope of every line that is parallel to the line on the graph ob Enter the correct answer. 6 4 OOO DONE Clear al N ? (-8,0) 10-12 pop -6 ko 8 ४ 2 2 8 do
Step-by-step explanation:
x=-6 y= 0
x0 y= -1
y=mx+b
b= -1
0= -6m -1
-6m= 1
m= -1/6
parallel lines have the same slope
slope = -1/6
Use the given information to answer the questions and interpret key features. Use any method of graphing or solving. Round to one decimal place, if necessary.
The trajectory of a golf ball in a chip from the rough has a parabolic pattern. The height, in feet, of the ball is given by the equation h(x) -.25x^2 + 3.42, where x is the number of feet away from the golf club (along the ground) the ball is.
The ball starts ____ feet above the ground.
The ball reaches a maximum height of _____ feet at a horizontal distance of ____ feet away from the golf club 19 it was hit with
The ball returns to the ground at about ____ feet away.
How many cups of flour are required to make 9 dozen cookies? ( write your answer as a mixed number) Demonstrate your method of choice
Answer:
45/16
Step-by-step explanation:
[tex]1 \frac{1}{4} = 4[/tex]
[tex]x = 9 [/tex]
[tex]x = 1 \frac{1}{4} \times 9 \div 4[/tex]
[tex]x = \frac{5}{4} \times 9 \div 4[/tex]
[tex]x = \frac{45}{16} [/tex]
The table shows the proof of the relationship between the slopes of two perpendicular lines. What is the missing statement in step 2?
Answer:
[tex]\frac{AB}{BC} = \frac{CE}{ED}[/tex]
Step-by-step explanation:
Given
The attached proof
Required
Complete the missing piece
In (a), we have:
[tex]\triangle ABC \to \triangle CED[/tex]
This implies that, the following sides are similar:
[tex]AB \to CE[/tex]
[tex]AC \to CD[/tex]
[tex]BC \to ED[/tex]
An equation that compares the triangle can be any of:
[tex]\frac{AB}{BC} = \frac{CE}{ED}[/tex]
[tex]\frac{AB}{AC} = \frac{CE}{CD}[/tex]
.....
From the options;
[tex]\frac{AB}{BC} = \frac{CE}{ED}[/tex] is true
Identify the transformation that occurs to create the graph of g(x). g(x)=f(x)-7
Answer:
g(x) is obtained by shift the function f(x) down 7 units by subtracting 7 units from f(x).
Step-by-step explanation:
We are given that
[tex]g(x)=f(x)-7[/tex]
We have to identify the transformation that occurs to create the graph of g(x).
To identify the transformation that occurs to create the graph of g(x)
We will subtract the 7 from f(x).
Let f(x) be any function
[tex]g(x)=f(x)-k[/tex]
It means g(x) obtained by shift the function f(x) down k units by subtracting k units from f(x).
Therefore, g(x) is obtained by shift the function f(x) down 7 units by subtracting 7 units from f(x).
Can I get the answer for those
Answer:
1) 5.64
2) 17.321
1) [tex]\frac{21}{28}[/tex]
2) [tex]\frac{16}{34}[/tex]
3) [tex]\frac{28}{35}[/tex]
4) [tex]\frac{32}{24}[/tex]
Step-by-step explanation:
SOH - CAH - TOA
Sin = [tex]\frac{O}{H}[/tex] Cos = [tex]\frac{A}{H}[/tex] Tan = [tex]\frac{O}{A}[/tex]
O = opposite, A = adjacent, H = hypotenuse
First two, use Pythagorean Theorem
If you want to calculate the angle on the last 4, use inverse of function and put in the ratio.
For example :
1) Tan Z = [tex]\frac{21}{28}[/tex]
[tex]Tan^{-1}[/tex] ( [tex]\frac{21}{28}[/tex])
Z = 36.9°
What is the sum of the 14th square number and the 3rd square number?
Answer:23
Step-by-step explanation:
solve the system of equation — 3х + бу = 9
5х + 7y = -49
Answer:
y = 64/3
x = -119/3
Step-by-step explanation:
3х + 6у = 9 => 5*3x+5*6у = 9*5 => 15x+30у=45 (1)
5х + 7y = -49 => 3*5x + 3*7y = -49*3 => 15x+21y=-147 (2)
(1)-(2) => 9y = 192 => y = 64/3
x = -119/3
True/False Questions - one attempt tor each question
If f is a decreasing function on an interval, then f'(x) > 0 on that interval.
True
False
Submit Question
Answer:
False
Step-by-step explanation:
f'(x) would be a negative number. Hence less than zero.
find the exact value cos5pi/6
Answer:
[tex] - \frac{ \sqrt{3} }{2} [/tex]
Step-by-step explanation:
Unit circle
Solve this equation log3X + log3(x-6) = log3 7
Hello!
log₃(x) + log₃(x - 6) = log₃(7) <=>
<=> log₃(x * (x - 6)) = log₃(7) <=>
<=> log₃(x² - 6x) = log₃(7) <=>
<=> x² - 6x = 7 <=>
<=> x² - 6x - 7 = 0 <=>
<=> x² + x - 7x - 7 = 0 <=>
<=> x * (x + 1) - 7 * (x + 1) = 0 <=>
<=> (x + 1) * (x - 7) = 0 <=>
<=> x + 1 = 0 and x - 7 = 0 <=>
<=> x = -1 and x = 7, x ∈ { 6; +∞ } <=>
<=> x = 7
Good luck! :)
RESOLVER LOS SIGUIENTES SISTEMAS DE ECUACIONES APLICANDO EL METODO DE SUSTITUCION
2x +3y = 2
-6x + 12y = 1
Answer:
x = 1/2; y = 1/3
Step-by-step explanation:
2x + 3y = 2 Eq. 1
-6x + 12y = 1 Eq. 2
Eq. 1
2x + 3y = 2
2x = -3y + 2
x = -3/2 y + 1
Eq. 2
-6x + 12y = 1
De Eq. 1 sabemos que x = -3/2 y + 1
-6x + 12y = 1
-6(-3/2 y + 1) + 12y = 1
9y - 6 + 12y = 1
21y - 6 = 1
21y = 7
y = 7/21
y = 1/3
Eq. 1
2x + 3y = 2
2x + 3(1/3) = 2
2x + 1 = 2
2x = 1
x = 1/2
Respuesta: x = 1/2; y = 1/3
please help i guess on a
Answer:
A = (2, 2)
B = (3, -1)
C = (-1, 0)
Step-by-step explanation:
To translate a point, you have to translate each individual point. At the bottom it shows <-2,3>, therefore you have to translate x 2 units to the left (because it's negative meaning the number is going away from 0, and 3 units to the right because 3 is a positive number.)
First Point A:
x: 4 - 2 = 2; y: -1 + 3 = 2
Second Point B:
x: 5 - 2 = 3; y: -4 + 3 = -1
Lastly, Point C:
x: 1 - 2 = -1, y: -3 + 3 = 0
I hope this helps!
Marina spent $13.50 at the grocery store. She bought pears, kiwis, and pineapples. Pears cost $0.50 each, pineapples cost $1.50 each, and kiwis are $0.30 each. How many did she buy if she bought 9 more pears than pineapples and 2 fewer kiwis than pears?
Answer:
Number of pineapples= 10
number of pears = 19
number of kiwis = 10 -2 = 8
Step-by-step explanation:
Cost of a pear = $ 0.50
Cost of a pineapple = $ 1.5
cost of a kiwi = $ 0.3
Let the pineapples = p
Number of pears = 9 + p
Number of kiwis = p - 2
The cost is
0.15 p + 0.5 (9 + p) + 0.3 (p - 2) = 13.50
0.15 p + 4.5 + 0.5p + 0.3 p - 0.6 = 13.50
0.95 p = 9.6
p = 10
Answer: There is 3 pineapples, 12 pears and 10 kiwis
Hope this help :)
Joaquin drew the triangle below.
On a coordinate plane, triangle K L J has points (3, 6), (4, 0) and (negative 5, 0).
Which statement must be true about a figure that is congruent to Joaquin’s triangle?
It has two angles on the x-axis.
It has a side that is 9 units long.
It has a side that lies on the x-axis.
It has an obtuse angle.
Answer:
It has a side that is 9 units long.
Step-by-step explanation:
Answer:
B) It has a side that is 9 units long.
Step-by-step explanation:
Since it does not have two angles on the X-axis, a side that lies on the X-axis, or an obtuse angle the reasonable answer would be B as it is true, and all of the others are false.
solve the system of equations using substitution or graphing.
Step-by-step explanation:
I think substitution would be the easiest since you already have one of the variables solved for.
[tex]y=-x^2+4x+5\\y=x+1\\x+1=-x^2+4x+5\\x^2-3x-4=0\\(x-4)(x+1)=0\\x-4=0\\x=4\\x+1=0\\x=-1[/tex]
(You can just set the equations equal to each other since they both equal y).
Now, to get the points, plug in x = 4 and x = -1 into one of the equations (I'm going to plug them into y = x+1 because that one is much simpler)
[tex]y(4)=4+1\\y(4)=5\\y(-1)=-1+1\\y(-1)=0[/tex]
So, your final points are:
(4,5) and (-1,0)
Answer: A
Step-by-step explanation:
We can use substitution to solve this problem. Since we are given y=-x²+4x+5 and y=x+1, we can set them equal to each other.
-x²+4x+5=x+1 [subtract both sides by x]
-x²+3x+5=1 [subtract both sides by 1]
-x²+3x+4=0
Now that we have the equation above, we can factor it to find the roots.
-x²+3x+4=0 [factor out -1]
-1(x²-3x-4)=0 [factor x²-3x-4]
-1(x+1)(x-4)=0
This tells us that x=-1 and x=4.
We can narrow down our answer to A, but let's plug in those values to be sure it is correct.
-(-1)²+4(-1)+5=(-1)+1 [exponent]
-1+4(-1)+5=-1+1 [multiply]
-1-4+5=-1+1 [add and subtract from left to right]
0=0
-------------------------------------------------------------------------------------------
-(4)²+4(4)+5=(4)+1 [exponent]
-16+4(4)+5=4+1 [multiply]
-16+16+5=4+1 [add and subtract from left to right]
5=5
Therefore, we can conclude that A is the correct answer.
Determine the intercepts of the line
Y ——-,——-
X——-,——-
Answer:
(-8,0), (0,-6)
Step-by-step explanation:
i need helpp !!!!!!!!!!!
Answer:
In descending order, 1, 4, 3
Given the following formula, solve for r.
IM BEING TIMED PLEASE ANSWER ASAPPPPPP
solve this please:
1y2 + 3y − 6 + 4y − 7 + 2y2 + 3y2 − 8 + 5y
Answer:
just combine like terms, its that simple.
Step-by-step explanation:
(6^2)^4 simplify the expression
Answer:
36
Step-by-step explanation:
(6^2)^4
(6)^2+4
6^6
36
simplify the expression : (6²)⁴= (36)⁴= 1679616
Or
[tex]{6}^{2 \times 8} = 1679616[/tex]
Write – 90 5/8 as a decimal number.
Answer:
-90.625
Step-by-step explanation:
Answer:
[tex]-90~5/8\\[/tex]
[tex]Decimal=-90.625[/tex]
-------------------------------
~HOPE IT HELP....~
~HAVE A GREAT DAY!!~
Fill in the blanks with the correct verbs given below.
(croak, is ,brush, writes plays, chirp, combines, mows, are look , keeps rises ,has,
reflects leaves, walks, is)
1. Marry ......... to office every morning .Walking is good exercise.
2. We........ our teeth after dinner. It ..........them clean.
3. Salim......... for school everyday at 7:00 a.m.
4. The sun ..........at 5:00 a.m. these days. The days are getting longer.
5. The tiger ......an endangered animal. There are only 1410 tigers left.
6. Vikram Seth......... poetry, fiction and travelogues.
7. Sania Mirza......... tennis. She plays both singles and doubles.
8. Frogs....... ...and birds...........
9. Please ..........for my red shirt. I cannot find it.
10. The gardener ........ the loan once a week.
11. The moon ........the light of the sun.
12. The times of India......... a national newspaper.
13. The UN headquarters...... in Geneva.
14. Maya ........... a pet dog .Its name is Lily.
15. This book....... projects and activities.
Answer:
Fill in the blanks with the correct verbs given below.
(croak, is ,brush, writes plays, chirp, combines, mows, are look , keeps rises ,has,
reflects leaves, walks, is)
1. Marry ...keeps rises...... to office every morning .Walking is good exercise.
2. We...brush..... our teeth after dinner. It .....makes.....them clean.
3. Salim....wakes..... for school everyday at 7:00 a.m.
4. The sun ...rises.......at 5:00 a.m. these days. The days are getting longer.
5. The tiger chirp......an endangered animal. There are only 1410 tigers left.
6. Vikram Seth.....combines........ poetry, fiction and travelogues.
7. Sania Mirza....plays..... tennis. She plays both singles and doubles.
8. Frogs....croak... ...and birds.....chirp......
9. Please ....look......for my red shirt. I cannot find it.
10. The gardener .....mows....... the loan once a week.
11. The moon ...keep rises.....the light of the sun.
12. The times of India......writes....... a national newspaper.
13. The UN headquarters.....is..... in Geneva.
14. Maya ...has........ a pet dog .Its name is Lily.
15. This book....writes..... projects and activities
Given the following angles, what ray is the common side of CFD and ZDFE?
Answer:
B. Ray FD
Step-by-step explanation:
A common side of two angles is the side shared by the two angles. It is part of the sides that forms both angles.
The common side of <CFD and <DFE is therefore ray FD. Ray FD is part of the sides that forms <CFD and also <DFE.
Answer:
B. Ray FD
Step-by-step explanation:
A common side of two angles is the side shared by the two angles. It is part of the sides that forms both angles.
The common side of <CFD and <DFE is therefore ray FD. Ray FD is part of the sides that forms <CFD and also <DFE.
The graph below is the graph of a function.
10
- 10
10
- 10
True
B. False
Answer:
hgfyjtdjtrxgfyfguktfkgh
Step-by-step explanation:
hgfytrdutrc
Least to greatest 22,755 20,564 2,3805
Least to greatest: 20,564 22,755 2,3805
Read the following scenario, and then answer the question.
Juan assumes that the temperature of the hot tea cooling on his desk can be modeled with an exponential function like this one: T(t)=179(0.92)t. He bases his assumption on the following: The tea cools about 8% every minute. The tea's current temperature is around 179 degrees Fahrenheit.
Which explanation correctly addresses Juan's assumption?
He is incorrect. The tea will cool linearly since it cools at the same number of degrees every minute.
He is correct. The tea will cool exponentially since it cools at a percentage rate every minute.
He is incorrect. The tea will cool along the curve of a parabola since it cools at an increasing percentage rate every minute.
9514 1404 393
Answer:
(b) He is correct. The tea will cool exponentially since it cools at a percentage rate every minute.
Step-by-step explanation:
Newton's Law of Cooling says the change in temperature is proportional to the temperature. This relation gives rise to an exponential function describing the temperature.
In this description, the temperature referred to is the difference between the temperature of the object and the temperature of the environment to/from which heat is being transferred.
Juan is only partially correct. The function is exponential, but the temperature that should be used in his equation is not the temperature of the tea, but the temperature difference between the tea and his desk.
__
The curve is not linear and not parabolic, excluding the other answer choices.
Suppose that you and a friend are playing cards and you decide to make a friendly wager. The bet is that you will draw two cards without replacement from a standard deck. If both cards are diamonds, your friend will pay you $296. Otherwise, you have to pay your friend $17.
What is the expected value of your bet?
Answer:
False because $296=$296
