The concentration of active ingredient in a liquid laundry detergent is thought to be affected by the type of catalyst used in the process. The standard deviation of active concentration is known to be 3 grams per liter regardless of the catalyst type. Ten observations on concentration are taken with each catalyst, and the data follow:
Catalyst 1: 57.9, 66.2, 65.4, 65.4, 65.2, 62.6, 67.6, 63.7, 67.2, 71.0
Catalyst 2: 66.4, 71.7, 70.3, 69.3, 64.8, 69.6, 68.6, 69.4, 65.3, 68.8.
a. Find a 95% confidence interval on the difference in mean active concentrations for the two catalysts. Find the P-value.
b. Is there any evidence to indicate that the mean active concentrations depend on the choice of catalyst? Base your answer on the results of part (a).
c. Suppose that the true mean difference in active concentration is 5 grams per liter. What is the power of the test to detect this difference if α = 0.05?
d. If this difference of 5 grams per liter is really important, do you consider the sample sizes used by the experimenter to be adequate? Does the assumption of normality seem reasonable for both samples?
Answer:
a. The 95% C.I. is approximately -5.83 < μ₁ - μ₂ < -0.57
b. Yes
c. The power of the test is 0.03836
d. The sample size can be considered adequate
Step-by-step explanation:
a. The given data in the study
Catalyst 1: 57.9, 66.2, 65.4, 65.4, 65.2, 62.6, 67.6, 63.7, 67.2, 71.0
Catalyst 2: 66.4 , 71.7, 70.3, 69.3, 64.8, 69.6, 68.6, 69.4, 65.3, 68.8
Using the Average, Standard Deviation function from Microsoft Excel, we have;
The mean for Catalyst 1, [tex]\overline x_1[/tex] = 65.22
The standard deviation for catalyst 1, σ₁ = 3.444416
The mean for Catalyst 2, [tex]\overline x_2[/tex] = 68.42
The standard deviation for catalyst 2, σ₂ = 2.22401
The 95% confidence interval on the difference in mean is given as follows;
[tex]\left (\bar{x}_1-\bar{x}_{2} \right ) \pm z_{c}\sqrt{\dfrac{\sigma _{1}^{2}}{n_{1}} + \dfrac{\sigma_{2}^{2}}{n_{2}}}[/tex]
The critical-z for a 95% confidence interval = 1.96
Therefore, we have;
[tex]\left (65.22-68.42 \right ) \pm 1.96 \times \sqrt{\dfrac{3^{2}}{10} + \dfrac{3^{2}}{10}}[/tex]
Therefore, we have;
The 95% C.I. is approximately -5.83 < μ₁ - μ₂ < -0.57
The test statistics is given as follows;
[tex]z=\dfrac{(\bar{x}_{1}-\bar{x}_{2})}{\sqrt{\dfrac{\sigma_{1}^{2} }{n_{1}}-\dfrac{\sigma _{2}^{2}}{n_{2}}}}[/tex]
Therefore we have;
[tex]z=\dfrac{(65.22-68.42)}{\sqrt{\dfrac{3^{2} }{10}+\dfrac{3^{2}}{10}}} = -2.385[/tex]
The p-value = P(Z<-2.39 or Z > 2.39) = 2P(Z<-2.39) = 2 × 0.00842 = 0.01684
b. From the confidence interval which range from approximately -5.83 to -0.57 and does not include 0, therefore, there is a difference in mean active concentration which depends on the choice of catalyst
c. The power of the test
The sample mean difference is given as follows;
[tex]\left (\bar{x}_1-\bar{x}_{2} \right ) = \pm z_{c}\sqrt{\dfrac{\sigma _{1}^{2}}{n_{1}} + \dfrac{\sigma_{2}^{2}}{n_{2}}}[/tex]
Therefore, we have;
[tex]\left (\bar{x}_1-\bar{x}_{2} \right ) = \pm 1.96 \times \sqrt{\dfrac{3^{2}}{10} + \dfrac{3^{2}}{10}} = \pm 2.6296[/tex]
The z-value is given as follows;
[tex]z=\dfrac{(\bar{x}_{1}-\bar{x}_{2})-(\mu_{1}-\mu _{2} )}{\sqrt{\dfrac{\sigma_{1}^{2} }{n_{1}}-\dfrac{\sigma _{2}^{2}}{n_{2}}}}[/tex]
μ₁ - μ₂ = 5
When [tex]\bar{x}_1-\bar{x}_{2} = 2.6296[/tex]
[tex]z=\dfrac{2.6296-5}{\sqrt{\dfrac{3^{2} }{10}-\dfrac{3^{2}}{10}}} \approx -1.7667918[/tex]
When [tex]\bar{x}_1-\bar{x}_{2} = -2.6296[/tex]
[tex]z=\dfrac{-2.6296-5}{\sqrt{\dfrac{3^{2} }{10}-\dfrac{3^{2}}{10}}} \approx -5.686768[/tex]
The power of the test is given by P = P(Z<-5.69) + P(Z>-1.77) = 0 + 0.03836 = 0.03836
The power of the test = 0.03836
d. The sample size is statistically adequate because the confidence interval of -5.83 < μ₁ - μ₂ < -0.57 has a value of -5 as a possible population difference in mean
The assumption of normality seems adequate because the confidence interval obtained by using the sample standard deviation is given as follows;
(-5.74, -0.66) which also contains -5 which is the difference in the population mean
Stephanie is going to paint the walls and ceiling of her bedroom. Her room is 18 feet long, 17 feet wide and 9 feet high.
What is the square footage (area) of the walls and ceiling that Stephanie will be painting?
The square footage Stephanie will be painting is ________ square feet. (Enter the number only)
How many gallons of paint does Stephanie have to purchase if each gallon of paint covers 250 square feet?
Stephanie will have to buy _____ gallons of paint. (Remember, you can only purchase a WHOLE number of gallons;Enter the number only)
If each gallon cost $23.75, how much will Stephanie spend on paint?
Stephanie will spend $________ on paint. (Enter the number only)
Answer:
55
Step-by-step explanation:
A sociologist wishes to conduct a poll to estimate the percentage of Americans who favor affirmative action program for women and minorities for admission to colleges and universities. What sample size should be obtained if she wishes the estimate to be within a margin of error of 0.04, with 95% confidence, if she uses a 2003 estimate of 0.55 obtained from a Gallup Youth Survey
Answer:
A sample of 595 should be obtained.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].
The margin of error is:
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
Estimate of 0.55
This means that [tex]\pi = 0.55[/tex]
95% confidence level
So [tex]\alpha = 0.05[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].
What sample size should be obtained if she wishes the estimate to be within a margin of error of 0.04?
This is n for which M = 0.04. So
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
[tex]0.04 = 1.96\sqrt{\frac{0.55*0.45}{n}}[/tex]
[tex]0.04\sqrt{n} = 1.96\sqrt{0.55*0.45}[/tex]
[tex]\sqrt{n} = \frac{1.96\sqrt{0.55*0.45}}{0.04}[/tex]
[tex](\sqrt{n})^2 = (\frac{1.96\sqrt{0.55*0.45}}{0.04})^2[/tex]
[tex]n = 594.2[/tex]
Rounding up,
A sample of 595 should be obtained.
pls help me answer number 2.
Answer: x=3, elimination method
Step-by-step explanation:
x=3
-7x-2y=-13 -> -7x-2y=-13
-(x-2y=11) -> -x+2y=-11
-----------------
-8x=-24
x = 3
elimination method
because you can easily eliminate one variable (y) using the elimination method
Six children want to share five chocolate bars fairly. How much chocolate will each child get?
Answer:
0.8 of a chocolate bar
Step-by-step explanation:
Bc 5 divided by 6 is 0.8
3/8+1/8=
Find the sum or difference
Answer:
Sum is 4/8
Difference is 2/8
Step-by-step explanation:
Sum is adding so add the numerators and denominators would be the same
Difference is subtraction
1. If y varies inversely as x and y = 2 when x = 10, find y when x = 5.
2. If y varies directly as z and inversely as x and y = 10 and z = 5 when x = 12.5, find z when y = 37.5 and x = 2.
Answer:
1.45
Step-by-step explanation:
I don't really know if this is right
a home mortgage for a home that costs $672096 with a 4% interest rate for 24 years. How much is the monthly payment for the mortgage with the interest?
9514 1404 393
Answer:
$3633.96
Step-by-step explanation:
The monthly payment is given by the amortization formula:
A = P(r/12)/(1 -(1 +r/12)^(-12t))
monthly payment for principal P at annual rate r for t years.
A = $672096(0.04/12)/(1 -(1 +0.04/12)^(-12·24)) = $3633.96
The monthly payment for the mortgage is $3633.96.
Mark stated that the slope of the line that passes through these two points (1, -19) and (-2, -7) is -¼. Is Mark correct? Explain. (show your work).
9514 1404 393
Answer:
no
Step-by-step explanation:
The slope formula is ...
m = (y2 -y1)/(x2 -x1)
We can use the values ...
(x1, y1) = (1, -19)
(x2, y2) = (-2, -7)
Putting these into the formula gives ...
m = (-7 -(-19))/(-2 -1) = 12/-3 = -4
The slope is -4, not -1/4. Mark is incorrect.
Jason can water all the plants at the botanical
garden in 32 minutes. Celia can water them in
25 minutes. If they work together, about how long
will it take for them to water the plants?
Answer:
If they water the plants in the garden together then it will take about 15 minutes because when they do it seperatly it takes about 30 minutes. So if they do it together, they are cutting work in half. And half of 30 is 15.
Step-by-step explanation:
32 rounded is 30.
25 rounded is 30.
30/ 2 = 15
Which table of the values can be defined by the function,y=4x-3
Answer:
B
Step-by-step explanation:
Ms. Monet gave 2 1/2 cups of red paint to each of her 20 students. How many quarts
of red paint did she give out?
What is the radius of a circle that has an approximate circumference of 81.64 meters? (Use 3.14 for ).
r =
m
Answer:
r=13
Step-by-step explanation:
81.64/3.14=26(diameter)
26/2=13(radius)
What percentage of 400=104 pls help me
Answer:
26%
Step-by-step explanation:
To find the percentage of a number, I find it's often helpful to first write it as a fraction: [tex]\frac{104}{400}[/tex] .
Percentages can be represented as a fraction by putting them over 100, eg. 25% is [tex]\frac{25}{100}[/tex]
.
Therefore, to get [tex]\frac{104}{400}[/tex] into a percentage, we need to change that 400 on the bottom to 100. How do we do that? Divide by four. However, anything we do to the bottom of a fraction, we must do to the top, so we divide both by four:
[tex]\frac{\frac{104}{4} }{\frac{400}{4} }[/tex] = [tex]\frac{26}{100}[/tex]
As we saw earlier, if a fraction has 100 at the bottom, then the top of the fraction is the percentage. So 104 is 26% of 400.
Select the correct answer. The graph of the function is shown f(x)=sin(x). What is the domain of the function? PLATO USERS
Answer:
Domain: (−∞,∞),{x|x∈R}
Step-by-step explanation:
the domain will be Domain: (−∞,∞),{x|x∈R} because
The domain of the expression is all real numbers except where the expression is undefined. In this case, there is no real number that makes the expression undefined.
Answer: Option C: (−∞,∞)
Step-by-step explanation:
answer is for plato
BRAINLIEST FOR CORRECT ANSWER, IM FAILING SCHOOL AND NEED HELP ASAP. EVEN OFFICIAL HELP COUNTS
Answer:
Verifal angles I think but I'm not necessarily sure!!!
PLEASE HELP !!!! ILL GIVE BRAINLIEST !!!
Answer:
1) Congruent
2) Vertical angles
3) 12x - 18 = 8x + 10
4) x = 7
Step-by-step explanation:
1)
Congruent because they're vertical angles.
2)
Vertical angles
3)
12x - 18 = 8x + 10
4)
12x - 18 = 8x + 10
12x - 8x = 10 + 18
4x = 28
x = 7
which sequence of transformations map triangle RST to triangle LMN? D0.5
Answer:
yeah my boy i think your right
Step-by-step explanation:
Given x3/4 find a and b when changing to radical form a (square root) b
Answer:
0.9644
Step-by-step explanation:
40 POINTS !! 40 POINTS !!
PLEASE HELP , DONT SKIP !
NO LINKS OR FILES.
Answer:
Its only 5 point but ok
its $3.44 per quart
Step-by-step explanation:
Please help me with this
−3+5+6g=11−3g
-Aster
Answer:
g=1
Step-by-step explanation:
6g+3g=-3g+9+3g, add 3g to both sides and you get closer to the answer
Answer:
g=1
Step-by-step explanation:
solved and got the same answer
whoever gets this correct first gets brainlest
Answer:
f(x) = 4*(5/2)^x
Step-by-step explanation:
First, we know that our function has the points:
(0, 4)
(1, 10)
(2, 25)
The first one (0, 4) means that:
f(0) = 4.
Then you can evaluate the four given functions in x = 0 and see which ones meet this condition (have the outcome equal to 4)
Here we can discard the function f(x) = 15*x - 5 because:
f(0) = 15*0 - 5 = -5
Then this function is discarded.
Now let's look at the second point, (1, 10)
This means that f(1) = 10
Then you can evaluate the remaining functions in x = 1, and see if the outcome is equal to 10.
Here we can discard the first function f(x) = (x + 2)^2 because:
f(1) = (1 + 2)^2 = 3^2 = 9
So the output is not 10 as we wanted.
(while for the other two functions we have)
for f(x) = 6*x + 4
f(1) = 6*1 + 4 = 10
for f(x) = 4*(5/2)^x
f(1) = 4*(5/2)^1 = 4*(5/2) = (4/2)*5 = 10
Now we use the last point, (2, 25)
This means that when x = 2, the outcome needs to be equal to 25.
For the function f(x) = 6*x + 4 we have:
f(2) = 6*2 + 4 = 12 + 4 = 16
So we can discard this one.
Then we could conclude that the remaining option is the correct one, but let's ceck.
f(x) = 4*(5/2)^x
then for x = 2
f(2) = 4*(5/2)^2 = 4*(25/4) = 25
correct.
Then the correct option is f(x) = 4*(5/2)^x
please help me out on this..............
Answer:
Option #2: 32 ÷2
Step-by-step explanation:
Take Note: There are 2 cups in a pint.
Since we are converting cups TO pints.... the number should (logically) be smaller. That eliminates the last two options.
Referring back to our note, it is only sensible to eliminate the first option since there are only 2 cups per pint, NOT 4.
In the end, you should have gotten option 2 which is 32÷2.
Can someone help me with this Geometry question? Will mark Brainliest.
Answer:
2 : 5
Step-by-step explanation:
4/10 = 8.6/21.5 = 10/25 because all ratios equal 2/5
Answer:
2:5
Step-by-step explanation:
all the ratios are equal
A set of two or more equations with the same variables is called a system of equations. When you set the
two expressions that are equal to the same variable equal to each other, like you did in the previous lesson,
you are using the Equal Values Method of solving a system of equations. Use the Equal Values Method to
solve the following problem.
It is time to cool off on a hot summer day! Team Sunshine is filling an inflatable kiddie pool from a garden
hose. The pool has 30 gallons in it and Team Sunshine is adding 8 gallons per minute with a garden hose.
Next door, Team Breeze's pool is already filled with 180 gallons of water. They are emptying the pool at 5
gallons per minute with buckets.
Write two equations to represent the situation. Use the equations to find how long it takes until both pools
have the same amount of water. Check your calculations.
Answer:
Both pools will have the same amount of water after 11 minutes and 32 seconds.
Step-by-step explanation:
Since Team Sunshine is filling an inflatable kiddie pool from a garden hose, and the pool has 30 gallons in it and Team Sunshine is adding 8 gallons per minute with a garden hose, while next door, Team Breeze's pool is already filled with 180 gallons of water, and they are emptying the pool at 5 gallons per minute with buckets, to determine how long it will take until both pools have the same amount of water, the following calculation must be performed:
Team Sunshine:
30 + (8X) = T
30 + 8x10 = 110
30 + 8x11 = 118
30 + 8x12 = 126
30 + 8x11.5 = 122
30 + 8x11.6 = 122.8
30 + 8x11.55 = 122.4
30 + 8x11.54 = 122.3
Team Breeze:
180 - (5X) = T
180 - 5x11 = 125
180 - 5x12 = 120
180 - 5x11.5 = 122.5
180 - 5x11.6 = 122
180 - 5x11.55 = 122.25
180 - 5x11.54 = 122.3
1 = 60
0.54 = X
0.54 x 60 = X
32.4
Thus, both pools will have the same amount of water after 11 minutes and 32 seconds.
Please Help! SCAMMERS WILL BE REPORTED! Use Cramer's Rule to solve the following system
-2x- 6y = -26
5x + 2y = 13
Answer:
x=1,y=4
Step-by-step explanation:
x=1,y=4
Given the following information, find the length of the missing side. Leave your answer as a simplified radical.
Answer:
Cd equals the square root of 3
Answer: 2 square root 3
Step-by-step explanation:
other user's answer
Pictures in order !
Answer:X=10
Step-by-step explanation: 3x-2=2x+8 If that's what you're looking for
500 people were surveyed about their favorite type of pet. 55% of the people said
"dog", 1/10 said "cat", 0.3 said "bird", and the rest said "other". How many people
responded "other"?
Answer:
25/500 or 5% said 'other'
Step-by-step explanation:
55% = 275 (dog)
1/10 = 50 (cat)
0.3 = 150 (bird)
Total = 475
475 out of 500 (95%) gave an answer other than 'other'
Jim qualifies for $0 down payment but makes a $2,500 down payment on his car purchases anyway. Will this payment help or hurt him
Answer:
help him
Step-by-step explanation:
Paying a $2,500 down payment on an automobile would normally benefit Jim. He reduces the total amount of the loan for the vehicle he will need to take out by making a down payment, which reduces the cost of his monthly payments and the amount of interest he will have to pay over the life of the loan. Furthermore, having a down payment increases his chances of getting approved for a loan or receiving a cheaper interest rate.
What is Down payment?A down payment is an upfront cash payment made when purchasing a significant ticket item like a car or a house. The down payment is often a proportion of the total cost of ownership and is made in order to lower the amount of financing required. Lower monthly payments or a shorter loan term are sometimes the outcome of a higher down payment.
A down payment is an initial up-front payment in part for the purchase of a large item or service, such as a car or a house. It is normally paid in cash or in the form of an equivalent at the time the transaction is completed. The balance of the payment is then financed by a loan of some kind.
Therefore, paying a $2,500 down payment on an automobile would normally benefit Jim.
Learn more about Down payment, here:
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