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.
6) Four bacteria are placed in a petri dish. The population will double every day. The formula for the
number of bacteria in the dish on day tis
N(t) = 4(2)^t
where t is the number of days after the four bacteria are placed in the dish. How many bacteria are
in the dish five days after the four bacteria are placed in the dish?
Answer:
128
Step-by-step explanation:
N(t) = 4(2)^t
N(t) = 4(2)^5
N(t) = 4(32)
N(t) = 128
The number of bacteria that are
in the dish five days after the four bacteria are placed in the dish is; 128 bacteria
We are given the formula for the
number of bacteria in the dish on day as;
N(t) = 4(2)^t
Where t is number of days after the four bacteria are placed in the dish.
Now we are told tof find the number of bacteria in the dish after 5 days.
Thus, we would put 5 for t in the given equation to get;
N(5) = 4(2)^5
N(5) = 4(32)
N(5) = 128
Read more about exponential growth at; https://brainly.com/question/23766914
1/3 ( − 7/4 k +1) − 10/3 k = − 13/8
Answer:
k = [tex]\frac{1}{2}[/tex]
Step-by-step explanation:
Can i have Brainllest
Answer:
k = 1/2
Step-by-step explanation:
can i have brainliest
PLEASE SOMEONE HELP I WILL GIVE BRAINLIEST
(Look at the picture)
The similarity ratio of two similar triangles is equal to the ratio of their corresponding sides :
Similarity ratio = BA / GF = BC / GH = CA / HF
Similarity ratio = 18 / 9 = 14 / 7 = x / 6
x / 6 = 2
multiple sides by 6
6 × x / 6 = 6 × 2
simplification
x = 12
HELP ASAP!!!! 20 POINTS!!
Answer:
Can you upload this as a jpg, I can't open it to asnwer. Also, you listed 10 points not 20.
Step-by-step explanation:
giving out brainliest answer !!!! help me out asap please !!!!
Answer:
8.07
Step-by-step explanation:
sin(48)=x/6
6sin(48)=x
POINTS UP FOR GRABS TAKE IT QUICK
Answer:
omg
Step-by-step explanation:
wowo .. . . . . . . . . . . . . . . . .
Answer:
Thanks so muchhh!! I'm really bad at math so I post questions alot so I dont have many points often. :)
help plz its a mathematical punnet square
Answer:
X 2 -7
-9 -18 126
3 -54 -6,804
1944 7.71
0.00396604938
Step-by-step explanation:
I tried. Sorry if it's wrong I've never done a mathematical punnet square before.
The equation shown has an unknown number. Write a fraction that makes the equation true.
? + 2/3 = 3/4
What is the answer please help
Answer:
7
Step-by-step explanation:
Mode is the value that appears most often. 7 appears the most often in this list.
Unit rates can be helpful with creating a ratio table and plotting the equivalent ratios on a coordinate plane. Explain why. PLEASE ANSWER ASAP AND PLEASE GIVE ME THE ANSWER!!!
Answer:
Unit rate is often a useful means for comparing ratios and their associated rates when measured in different units. The unit rate allows us to compare varying sizes of quantities by examining the number of units of one quantity per one unit of the second quantity. This value of the ratio is the unit rate.
Solve for x.
2
8
4
X
Answer:
Impossible
Step-by-step explanation:
This diagram is not correctly stating the question
A teacher chooses a student at random from a class of 25 boys. Which BEST describes the probability that the student chosen is a boy?
A) impossible
B) unlikely
C) likely
D) certain
Which best describes the solutions to the system?
x + y=− 4
−2x − 2y =0
A one solution
B (0,0)
C no solution
D infinitely many
Answer:
A best descibes it as we can say its the only answer
Step-by-step explanation:
using symaltaneous equation is the only way to solve it
QUICK IG? GIVING BRAINLIEST TO THE PERSON WHO ANSWERS
Answer:
So the answer is 241.5 mL IM VERY VERY SURE I converted 1 liter to ml and got 1000ml so i did 1000ml minus 758.5ml and got 241.5 mL
Answer is 241.5 mL
BRAINLIEST PLEASE TYSM
WILL MARK BRAINLIEST
Solve for y
110
75
100
55
Answer:
Answer for Y is 100....
Answer:
100
sorry if my answer is wrong
Two investments totallng $47,500 produce an annual income of $3000. One investment ylelds 9% per year, while the other yields 6% per year. How much is invested at each rate?
Answer:
The correct answer is "$5000".
Step-by-step explanation:
The given values are:
Two investments totaling,
= $47,500
Annual income,
= $3000
One investment yields per year,
= 9%
Other yield,
= 6%
Let,
The amount invested in 9% will be "x".The amount invested in 6% will be "[tex]47,500-x[/tex]".Now,
⇒ [tex]0.09x+0.06(47,500-x)=3000[/tex]
⇒ [tex]0.09x+2850-0.06x=3000[/tex]
⇒ [tex]0.03x+2850=3000[/tex]
⇒ [tex]0.03x=150[/tex]
⇒ [tex]x=\frac{150}{0.03}[/tex]
⇒ [tex]x=5000[/tex]
*Determine the number of solutions the equation below has.
3(1 + d)-5 = 3d - 2
Explain how you know .
Answer:
6
Step-by-step explanation:
because i know
PLEASE HELP
3/4x - 7 = 3 (1/6x +1)
Solve the linear equation and determine whether it’s one solution or infinite solution or no solution
Answer: one solution
Step-by-step explanation:
CONCEPT:
- One solution is when the final variable would be able to find a solution.
- Infinite solution is when the equations result in 0=0, meaning any number will fit
- No solution is when the equation results in both sides on equal.
SOLVE:
Given
3/4x-7=3(1/6x+1)
Expand Parenthesis
3/4x-7=1/2+3
Multiply both sides by the LCM of fractions (Least Common Multiple)
4(3/4x-7)=4(1/2x+3)
3x-28=2x+12
Subtract both sides by 2x
3x-28-2x=2x+12-2x
x-28=12
Add both sides by 28
x-28+28=12+28
x=40
Since we are able to get exactly one solution, there is only one solution.
Hope this helps!! :)
Please let me know if you have any quesionts
Solve equation by using the quadratic formula.
2x? + 13x = 0
Answer:
c
Step-by-step explanation:
Ethan's mom tried a new bean soup recipe. She used 2 cups of black beans and 5 cups of kidney beans. The family loved it, so she made a larger batch to freeze with 4 cups of black beans and 12 cups of kidney beans. Did the two batches have the same ratio of black beans to kidney beans?
no links, please
Answer:
no the amount of Kidney beans is not proportional to the amount of black beans
Step-by-step explanation:
Answer:
No. The two bathes do not have the same ratio
Step-by-step explanation:
cokb= Cups of kidney beans
cobb= Cups of black beans
2 cobb = 5 cokb x2
4 cobb = 10 cokb
so if we have
4 and 12 the soup is going to be more on hte cokb side
Find the greatest common factor of 10, 30, and 45.
Answer:
5
Step-by-step explanation:
∴ The greatest number that divides 10, 30, and 45 is [tex] { \underline{ \boxed{ \orange{ \tt{5}}}}} [/tex]
Hope it help ;)
10. A large shipment of video streaming devices is accepted upon delivery if an inspection of 20 randomly selected video streaming devices yields no more than 1 defective item. a. Find the probability that the shipment is accepted if 3% of the total shipment is defective. b. Find the probability that the shipment is accepted if 15% of the total shipment is defective.
Answer:
a) 0.8802 = 88.02% probability that the shipment is accepted
b) 0.1756 = 17.56% probability that the shipment is accepted if 15% of the total shipment is defective.
Step-by-step explanation:
For each item, there are only two possible outcomes. Either it is defective, or it is not. The probability of an item being defective is independent of any other item. This means that 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.
20 randomly selected video streaming devices
This means that [tex]n = 20[/tex]
a. Find the probability that the shipment is accepted if 3% of the total shipment is defective.
3% defective means that [tex]p = 0.03[/tex]
Probability of at most 1 defective is:
[tex]P(X \leq 1) = P(X = 0) + P(X = 1)[/tex]
In which
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 0) = C_{20,0}.(0.03)^{0}.(0.97)^{20} = 0.5438[/tex]
[tex]P(X = 1) = C_{20,1}.(0.03)^{1}.(0.97)^{19} = 0.3364[/tex]
[tex]P(X \leq 1) = P(X = 0) + P(X = 1) = 0.5438 + 0.3364 = 0.8802[/tex]
0.8802 = 88.02% probability that the shipment is accepted.
b. Find the probability that the shipment is accepted if 15% of the total shipment is defective
Now [tex]p = 0.15[/tex]. So
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 0) = C_{20,0}.(0.15)^{0}.(0.85)^{20} = 0.0388[/tex]
[tex]P(X = 1) = C_{20,1}.(0.15)^{1}.(0.85)^{19} = 0.1368[/tex]
[tex]P(X \leq 1) = P(X = 0) + P(X = 1) = 0.0388 + 0.1368 = 0.1756[/tex]
0.1756 = 17.56% probability that the shipment is accepted if 15% of the total shipment is defective.
Mrs. Carroll asked her students to write an exponential function that represents a growth rate of 15% each year with an initial value of 1,000. Which student completed the task correctly
Answer:
i need help with the same thing but no one cares
Step-by-step explanation:
10 \div (-2) = ?10÷(−2)=
Answer: -5 I'm pretty sure, the way you put it kinda made me confused
If a $6.00 ball was bought for $5.25, what was the percentage of the discount?
A. 25%
B. 12.5%
C. 15%
D. 20%
E. 75%
Please show work and I will make brainlist.
Answer:
B
Step-by-step explanation:
x% of 6 = 5.25
[tex]\frac{x}{100}[/tex] x 6 = 5.25
[tex]\frac{(5.25)(100)}{6}[/tex] = x
x = 87.5 %
discount = 100 - 87.5 %
= 12.5 %
Find f(-3) if f(x) = x 2.
A) 6
B-9
C)9
D-6
Answer: f(-3)=(-3)^2
f(-3)=9
the answer is C
Step-by-step explanation:
x+y+z=9
x-y-z=-1
x-y+z= 21
Which value is not in the solution, (x,y,z), of the
system?
1) -8.
2) ---6
3) 11
4) 4
the answer is (-8) because x=4, y=-6, z=11
These consists of more than 1 equation with unknown variables. The value that is not a solution in (x,y, z)is -8
System of equationsThese consists of more than 1 equation with unknown variables. Given the set of equations
x+y+z=9
x-y-z=-1
x-y+z= 21
Add 1 and 2
2x = 9 - 1
2x = 8
x = 4
Subtract 2 and 3
-2z = -22
z = 11
Determine the value of y
x +y + x = 9
4 + y + 11 = 9
y = 9 - 15
y = -6
Hence the value that is not a solution in (x,y, z)is -8
Learn more on system of equation here: https://brainly.com/question/25976025
#SPJ6
HELP!!!!!!ASAP!!!!!!
Answer:
Im only in middle school, sorry
Step-by-step explanation:
I have tips tho!
always write information down, only useful ones, and not like "jimmy love to play basketball" kin of stuff.
Think it through, dont just guess.
Hope this helps i guess,
-yuko
Anyone know this? Answer for cookie!
Answer:
no solution
Step-by-step explanation:
the value of 3x+2y can't be two different things at once
Answer: no solutions
Step-by-step explanation:
when the two equations have the same x and y values but a different y intercept they can not have any solutions because they are parallel
why is the equation of the line that has a slope of 4 and a y intercept of -7