Answer:
a) The 99% confidence interval for the difference of proportions is (0.0844, 0.3012).
b) We are 99% sure that the true difference in proportions is between 0.0844 and 0.3012. Since all values are positive, there is significant evidence at the 1 - 0.99 = 0.01 significance level to conclude that the proportion is the Fort Defiance region is higher than in the Indian Wells region.
Step-by-step explanation:
Before finding the confidence interval, we need to understand the central limit theorem and subtraction of normal variables.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]
Subtraction between normal variables:
When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.
Fort Defiance:
69 out of 210, so:
[tex]p_1 = \frac{69}{210} = 0.3286[/tex]
[tex]s_1 = \sqrt{\frac{0.3286*0.6714}{210}} = 0.0324[/tex]
Indian Wells:
22 out of 162, so:
[tex]p_2 = \frac{22}{162} = 0.1358[/tex]
[tex]s_2 = \sqrt{\frac{0.1358*0.8642}{162}} = 0.0269[/tex]
Distribution of the difference:
[tex]p = p_1 - p_2 = 0.3286 - 0.1358 = 0.1928[/tex]
[tex]s = \sqrt{s_1^2+s_2^2} = \sqrt{0.0324^2 + 0.0269^2} = 0.0421[/tex]
a. Find a 99% confidence interval for p1 -p2.
The confidence interval is:
[tex]p \pm zs[/tex]
In which
z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].
99% confidence level
So [tex]\alpha = 0.01[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.01}{2} = 0.995[/tex], so [tex]Z = 2.575[/tex].
The lower bound of the interval is:
[tex]p - zs = 0.1928 - 2.575*0.0421 = 0.0844[/tex]
The upper bound of the interval is:
[tex]p + zs = 0.1928 + 2.575*0.0421 = 0.3012[/tex]
The 99% confidence interval for the difference of proportions is (0.0844, 0.3012).
Question b:
We are 99% sure that the true difference in proportions is between 0.0844 and 0.3012. Since all values are positive, there is significant evidence at the 1 - 0.99 = 0.01 significance level to conclude that the proportion is the Fort Defiance region is higher than in the Indian Wells region.
Sport Chek conducts customer satisfaction surveys by having its customers complete questionnaires regarding their customer service experience. Their computer system automatically sends surveys to customers who spend more than $100 at their store. What type of bias might result?
a) Response Bias
b) Sampling Bias
c) Both response bias and sampling bias
d) Neither response bias or sampling bias
Answer:
b
Step-by-step explanation:
Because only the customers who spend more than $100 get to complete the form. The other customers wont be able to complete it(people who spent less than $100). thats why the answer would be sampling bias.
Look at images below. : ]
Answer:
1) A
B) 5.818 stops
Step-by-step explanation:
Number One is less than or equal to 21 because the person only has 21 dollars, so she can't spend more than 21.
B can be solved through the equation by first subtracting $5, and then dividing 2.75 by 16.
Write A linear equation in standard form the passes through the points (4,-2) and (2,6)
Answer:
Step-by-step explanation:
4 x + y =
14
need some help with this :)
===========================================================
Explanation:
All direct variation equations are of the form y = kx, for some constant k.
We know that y = -8 and x = 4 pair up together. Let's use these two values to find k
y = kx
-8 = k*4
-8/4 = k
-2 = k
k = -2
Therefore, we go from y = kx to y = -2x
We can then find y when x = -4
y = -2x
y = -2*(-4)
y = 8
Answer:
y∝x
y=kx
k=y/x
by putting values
k=-8/4
k= -2
now ,if x= -4
as, y=kx
hence, y= (-2)(-4)
y=8
Step-by-step explanation:
find the area of the shaded region
Answer:
22 cm²Step-by-step explanation:
Shaded area is the difference of the bigger circle and two smaller ones:
A = π(3²) - 2π(1²) = 7π = 7*3.14 ≈ 22 cm²♥️♥️♥️♥️♥️♥️♥️♥️♥️ help me
9514 1404 393
Answer:
AC = 2.0 mm = 41.3 kgStep-by-step explanation:
The sum of torques about the pivot point is zero when the system is in equilibrium. That means the total of clockwise torques is equal to the total of counterclockwise torques. For this purpose, torque can be modeled by the product of mass and its distance from the pivot. The uniform beam can be modeled as a point mass at its center.
__
a) Let E represent the location of the center of mass of the beam. So, AE = 1.5 m. Then the distance from C to E is AC-AE = AC -1.5 and the CCW torque due to the beam's mass is (16 kg)(AC -1.5 m).
The distance from B to C is 3 m - AC, so the CW torque due to the particle at B is (7 kg)(3 -AC m)
These are equal, so we have ...
16(AC -1.5) = 7(3 -AC)
16AC -24 = 21 -7AC . . . . . eliminate parentheses
23AC = 45 . . . . . . . . . . . add 7AC+24
AC = 45/23 ≈ 1.957 . . divide by the coefficient of AC
AC ≈ 2.0 meters . . . . rounded to 1 dp
__
b) The torques in this scenario are ...
M(0.7) = 16(0.8) +7(2.3) . . . . . . AD = 0.7 m, DE = 0.8 m, DB = 2.3 m
M = 28.9/0.7 ≈ 41.286 . . . . simplify, divide by the coefficient of M
M = 41.3 kg . . . . rounded to 1 dp
_____
Additional comment
Torque is actually the product of force and distance from the pivot. Here, the forces are all downward, and due to the acceleration of gravity. The gravitational constant multiplies each mass, so there is no harm in dividing the equation by that constant, leaving the sum of products of mass and distance.
Can somebody help me solve this ?
Step-by-step explanation:
volume of sphere = 288
based on formula, V = 4/3πr³
288 = 4/3(3.14)r³
288 = 4.187(r³)
r³ = 288/4.187
r =
[tex] \sqrt[3]{68.78} [/tex]
r = 4.09
= 4.1
HELP ASAP
What is the area of this polygon on a coordinate plane?
Answer:
Step-by-step explanation:
One way to find the area of any polygon is to find areas of all of its inside sections and then adding them together. For example, if I had a polygon made of a square stuck to a triangle, I could calculate the area of the polygon by adding the area of the square to the area of the triangle.
A computer is selling for $883 the finance value is $1077.26 under an 11% simple interest loan what is the length of the loan
Answer:
The length of the loan was 2 years.
Step-by-step explanation:
Given that a computer is selling for $ 883, and the finance value is $ 1077.26 under an 11% simple interest loan, to determine what is the length of the loan, the following calculation must be performed:
883 x 0.11 = 97.13
(1077.26 - 883) / 97.13 = X
194.26 / 97.13 = X
2 = X
Therefore, the length of the loan was 2 years.
Working at home: According to the U.S Census Bureau, 34% of men who worked at home were college graduates. In a sample of 500 women who worked at home, 170 were college graduates. Part: 0 / 30 of 3 Parts Complete Part 1 of 3 (a) Find a point estimate for the proportion of college graduates among women who work at home. Round the answer to at least three decimal places. The point estimate for the proportion of college graduates among women who work at home is .
Answer:
The answer is "0.340".
Step-by-step explanation:
[tex]n = 500\\\\x = 170[/tex]
Using formula:
[tex]\to \hat{p} = \frac{x}{n} = \frac{170}{500}=\frac{17}{50} =0.340[/tex]
What is the slope, m, and the y-intercept of the line that is graphed below?
On a coordinate plane, a line goes through points (negative 3, 0) and (0, 3).
Answer:
Slope: 1
Y-intercept: (0,3)
Step-by-step explanation:
The y intercept is when the slope reaches the y-axis line. In this case, it is given to us. Anything that is formed like this: (0, y) is the y-intercept.
Y intercept: (0, 3)
For slope, you can use the formula rise over run. [tex]\frac{Rise}{Run}[/tex]
From the picture, I have drawn the rise over run, which is [tex]\frac{3}{3}[/tex], which is also 1.
Slope: 1
Hope this helped.
Answer: 1
Step-by-step explanation: got it right on edge
A randomized study compared two drugs that are designed fo lower a person's serotonin level. It was found that over a 1-year period, those receiving Drug A decreased their serotonin level by a mean of 36 nanograms per millimeter. Those receiving Drug B decreased their serotonin level by a mean of 20 nanograms per millimeter. To determine whether the results are significant, the data are randomized and the difference of the means is shown in the dot plot. What is the best conclusion to make based on the data?
A. The difference of the means is significant because the rerandomizations show that it is outside the range of what likely happens by chance.
B. The difference of the means is not significant because the rerandomizations show that it is outside the range of what likely happens by chance.
C. The difference of the means is not significant because the rerandomizations show that it is within the range of what likely happens by chance.
D. The difference of the means is significant because the rerandomizations show that it is within the range of what likely happens by chance.
The best conclusion to make based on the data is: The difference of the means is significant because the re-randomizations show that it is outside the range of what could happen by chance.
Difference of meansGiven:
Drug A= Decrease serotonin level by means of 36 nanograms per millimeter
Drug B= Decrease serotonin level by means of 20 nanograms per millimeter
Hence,
When we take a look at the difference of means data that was given, we would see that the different of means is significant between the means of Drug A and Drug B due to chance or random variation.
Based on the fact that the re-randomizations indicate that it is outside the range of what could happen by chance.
Therefore the correct option is A.
Learn more about difference of mean here:https://brainly.com/question/6281520
#SPJ1
Answer:
The difference of the means is NOT significant because the rerandomizations show that it is within the range of what likely happens by chance
Step-by-step explanation:
Took the test and this is 100% the answer. Hope it helps.
Find the sum of -3x^2-4x+3 2x^2+3
please give me correct answer
Answer:
150 e udi,auwdbkhg
disha
eiwiwisj8293
ajesjhf
8ઈઘુઘ
write the equation of the graph, y=? SOMEBODY PLEASE HELP
Answer:
[tex]y=\left(6\right)^{x}\ -3[/tex]
Step-by-step explanation:
What are some acceptable ways to name an line
Answer:
If there are points that are named you can name it that way
Step-by-step explanation:
If there is a point and it's called A, and there is another point and it is called B, and they form a line together, you can call it "Line AB"
Step 3: Write the equation of the line that passes through the point (4,−1)
(
4
,
−
1
)
that is parallel to the line 2−3=9
Answer:
-
Step-by-step explanation:
-
Mark bought seeds, 5 packets of carrot seeds, 2 packets of
bean seeds, and 3 packets of pea seeds. If he randomly
selects 4 packets to plant, what is the probability that he
selects 2 packets of carrots, 1 packet of beans, and 1 packet
of peas?
Answer:
4/10=2/5 therefore the answer to 2/5
Use the graph of ƒ to find ƒ(2).
0.5
–8
–0.5
Does not exist
Answer:
Step-by-step explanation:
When you're looking to find things like f(2) and f(4) and f(-3000), etc. the number inside the parenthesis is an x value. Look to the graph, find that x value, and locate the y value that corresponds to it. f(2) = -8. f(-1) = 4. f(1) = -4. See?
Answer:
does not exist
Step-by-step explanation:
that what i put hope it helps
What type of line is PQ?
A. angle bisector
B. median
C. altitude
D. side bisector
Answer:
D
Step-by-step explanation:
RS is a side.
RQ = QS They are both equal to seven.
That means that the answer is A or D
Since the word side is in D, it must be the answer.
Use the given information to find the number of degrees of freedom, the critical values χ2L and χ2R, and the confidence interval estimate of σ. It is reasonable to assume that a simple random sample has been selected from a population with a normal distribution. Nicotine in menthol cigarettes 99% confidence; n=23, s=0.28 mg.
df = (Type a whole number.)
χ2L = (Round to three decimal places as needed.)
χ2R = (Round to three decimal places as needed.)
The confidence interval estimate of σ is __ mg < σ < __ mg. (Round to two decimal places as needed.)
Answer:
χ²R = 8.643
χ²L = 42.796
0.20 < σ < 0.45
Step-by-step explanation:
Given :
Sample size, n = 23
The degree of freedom, df = n - 1 = 23 - 1 = 22
At α - level = 99%
For χ²R ; 1 - (1 - 0.99)/2= 0.995 ; df = 22 ; χ²R = 8.643
For χ²L ; (1 - 0.99)/2 = 0.005 ; df = 22 ; χ²L = 42.796
The confidence interval of σ ;
s * √[(n-1)/χ²L] < σ < s * √[(n-1)/χ²R)]
0.28 * √(22/42.796) < σ < 0.28 * √(22/8.643)
0.2008 < σ < 0.4467
0.20 < σ < 0.45
The average weekly assignment score of students in a statistics class is 7 out of 10 points. The professor proposes new incentives to boost the score of the students (like providing internship contacts etc.) He hopes that the results of running this incentives plan for a trial during the next couple of weeks will enable him to conclude that the incentives he offers increase the average weekly assignment score of students. What is the null hypothesis.
A. The average weekly score is strictly more than or equal to 7.
B. The average weekly score is less than our equal to 7.
C. The average weekly score is strictly less than 7.
D. The average weekly score is strictly more than 7.
Answer:
B. The average weekly score is less than or equal to 7.
Step-by-step explanation:
The average weekly assignment score of students in a statistics class is 7 out of 10 points. Test if it has increased.
This means that at the null hypothesis it is tested that the mean score of the students has not increased, that is, it still is of at most 7, so:
[tex]H_0: \mu \leq 7[/tex]
And thus, the correct answer is given by option b.
Alejandro wants to adopt a puppy from an animal shelter. At the shelter, he finds eight puppies that he likes: a male and female puppy from each of the four breeds of and Labrador. The puppies are each so cute that Alejandro cannot make up his mind, so he decides to pick the dog randomly. Find the probability that Alejandro chooses a .
Answer:
Hence the required probability is, 3/4
Step-by-step explanation:
At the shelter, he likes :
a male coolie, a female coolie, a male boxer, a female boxer, a male beagle, a female beagle, a male Labrador, and a female Labrador.
Let, A denote the event of selecting a male coolie and B denote the event of selecting a male Labrador.
P(A) = 1/8 = P(B)
Here the probability of selecting a puppy except A & B is,
P(AUB)c = 1 - P(AUB) = 1 - { P(A) + P(B) } = 1 - 1/8 - 1/8 = 3/4
Please help with this question
9514 1404 393
Answer:
dy/dx = 2x +1
Step-by-step explanation:
The power rule can be used.
d/dx(x^n) = n·x^(n-1)
Then the derivative of x² is 2x¹ = 2x, and the derivative of x = 1x⁰ = 1.
The derivative of the function is ...
dy/dx = 2x +1
What is the slope of a line perpendicular to line A?
You flip a coin that is not fair, the prbability of heads on each flip is 0.7. if the coin shows heads, you draw a marble from urn h with 1 blue and 4 red marbles. if the coin shows tails, you draw a marble from urn t with 3 blue and 1 red marble. Find the following probabilities:
a. The probability of choosing a red marble.
b. The probability of choosing a blue marble, given that the coin showed heads.
c. The probability that the coin showed tails, given that the marble was red.
Solution :
P(H) = 0.7 ; P(T) = 0.3
If heads, then Urn H, 1 blue and 4 red marbles.
If tails, then Urn T , 3 blue and 1 red marbles.
a).
P ( choosing a Red marble )
= P (H) x P( Red from Urn H) + P (T) x P( Red from Urn T)
[tex]$=0.7 \times \frac{4}{5} + 0.3 \times \frac{1}{4}$[/tex]
= 0.56 + 0.075
= 0.635
b). If P (B, if coin showed heads)
If heads, then marble is picked from Urn H.
Therefore,
P (Blue) [tex]$=\frac{1}{5}$[/tex]
= 0.2
c). P (Tails, if marble was red)
[tex]$=P (T/R) = \frac{P(R/T)}{P(R)} \ P(T)$[/tex]
Where P (R/T) = P ( red, if coin showed tails)
[tex]$=\frac{1}{4}$[/tex]
= 0.25 (As Urn T is chosen)
P (R) = P (Red) = 0.635 (from part (a) )
P (T) = P (Tails) = 0.3
∴ [tex]$P(T/R) = \frac{0.25 \times 0.3}{0.635}$[/tex]
= 0.118
Trish's punch recipe calls for 8 liters of lemon-lime soda and 4 liters of cranberry juice, Jenny's punch recipe requires 7
liters of lemon-lime soda and 6 liters of cranberry juice. Which recipe has a higher ratio of lemon-lime soda to cranberry
juice?
( A, neither, the ratios are equivalent
B. Trish's recipe
c. Jenny's recipe
D. not enough information
Find the circumference of the circle.
10.1 in
Hint: C = xxd
x= 3.14
A.15.857 in
B.31.714 in
C.63.428 in
D.13.24 in
Step-by-step explanation:
c=3.14×3.14×10.1
=99.58196
The quadratic equation x^2 + 3x + 50 = 0 has roots r and s. Find a quadratic equation whose roots are r^2 and s^2.
Answer:
x^2 + 91x + 2500
-----------------------------------------------------------------------------
x^2 + 3x + 50
(x-r)(x-s)
-> x^2-(r+s)x+rs
rs = 50, r + s = -3
-> (rs)^2 = 2500
(r+s)^2 = 9
-> r^2 + 2rs + s^2 = 9
-> r^2 + 2(50) + s^2 = 9
-> r^2 + s^2 + 100 = 9
-> r^2 + s^2 = -91
(x-r^2)(x-s^2)
-> x^2-(r^2+s^2)x+(rs)^2
-> x^2 - (-91)x + 2500
x^2 + 91x + 2500
The 3rd and 6th term of a geometric progression are 9/2 and 243/16 respectively find the first term, common ratio, seventh term
Answer:
Hello,
Step-by-step explanation:
[tex]Let\ (u_n)\ the\ geometric\ progression.\\\\r\ is\ the\ common\ ratio.\\\\u_3=u_0*r^3\\u_6=u_0*r^6\\\\\dfrac{u_6}{u_3} =r^3=\dfrac{\frac{243}{16} }{\frac{9}{2} } =\dfrac{27}{8} =(\frac{3}{2} )^3\\\\\boxed{r=\dfrac{3}{2} }\\\\\\u_3=u_1*r^2 \Longrightarrow\ u_1=\dfrac{u_3}{r^2} =\dfrac{\frac{9}{2} }{(\frac{3}{2^2}) } =2\\\\\\u_7=u_6*\dfrac{3}{2} =\dfrac{729}{32}[/tex]
