Answer:
The point estimate that should be used in constructing the confidence interval is 0.11.
The 80% confidence interval for the difference in two proportions is (0.0856, 0.1344).
Step-by-step explanation:
Before building 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.
Midwest:
50% of 1380, so:
[tex]p_M = 0.5[/tex]
[tex]s_M = \sqrt{\frac{0.5*0.5}{1380}} = 0.0135[/tex]
South:
39% of 1300, so:
[tex]p_S = 0.39[/tex]
[tex]s_S = \sqrt{\frac{0.39*0.61}{1300}} = 0.0135[/tex]
Distribution of the difference:
[tex]p = p_M - p_S = 0.5 - 0.39 = 0.11[/tex]
So the point estimate that should be used in constructing the confidence interval is 0.11.
[tex]s = \sqrt{s_M^2+s_S^2} = \sqrt{0.0135^2+0.0135^2} = 0.0191[/tex]
Confidence interval:
[tex]p \pm zs[/tex]
In which
z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].
80% confidence level
So [tex]\alpha = 0.2[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.2}{2} = 0.9[/tex], so [tex]Z = 1.28[/tex].
The lower bound of the interval is:
[tex]p - zs = 0.11 - 1.28*0.0191 = 0.0856[/tex]
The upper bound of the interval is:
[tex]p + zs = 0.11 + 1.28*0.0191 = 0.1344[/tex]
The 80% confidence interval for the difference in two proportions is (0.0856, 0.1344).
7
Abdul's gas tank is
1
3
full. After he buys 12 gallons of gas, it is
full. How many gallons can Abdul's tank hold?
9
Answer:
27
Step-by-step explanation:
Let T be the capacity of the tank.
Since the tank was 1/3 full and ends up 7/9 full.
[tex]\frac{7}{9}[/tex]T - [tex]\frac{1}{3}[/tex]T = 12
Simplifying the left side of the equation, tells us how much 12 gallons fills.
[tex]\frac{4}{9}[/tex]T = 12
Now we solve for T:
T = 12*9/4
T = 27
From the picture, two cylindrical glasses of the same capacity. Find the diameter length (X) of a small glass of water.
8
12
14
10
Answer:
12
Step-by-step explanation:
πr²h=πr²h
π(4.5)²*10=π(x/2)²4.9
The sum of the measures of the angles of a triangle is 180. The sum of the measures of the second and third angles is four
times the measure of the first angle. The third angle is 10 more than the second. Let , y, and z represent the measures of
the first, second, and third angles, respectively. Find the measures of the three angles.
9514 1404 393
Answer:
(36°, 67°, 77°)
Step-by-step explanation:
The problem statement lets us write the equations ...
x + y + z = 180 . . . . sum of angles in a triangle
y + z = 4x . . . . . 2nd and 3rd total 4 times the first
z = y +10 . . . . . . 3rd is 10 more than 2nd
__
Substituting for z in the second equation, we have ...
y +(y +10) = 4x
y +5 = 2x . . . . . . divide by 2
y = 2x -5 . . . . . . rearranged
z = 2x +5 . . . . . . substitute for y in the last equation
Now, we can write the first equation entirely in terms of x:
x +(2x -5) +(2x +5) = 180
5x = 180
x = 36
y = 2(36) -5 = 67
z = 67 +10 = 77
The three angles are (x, y, z) = (36°, 67°, 77°).
1. Đường kính của một loại trục máy là một đại lượng ngẫu nhiên có phân phối chuẩn N (μ = 250mm, σ2 = 25mm2). Trục máy được gọi là hợp quy cách nếu đường kính từ 245mm đến 255mm. Cho máy sản xuất 100 trục. Tính xác suất để:
a. Có 50 trục hợp quy cách.
b. Có không quá 80 trục hợp quy cách
Answer:
cannot understand the language man
but please follow
What is the value of p?
A. 125°
B. 45°
C. 35°
D. 550
Answer:
C- 35 °
Step-by-step explanation:
Interior angle adjacent to 90° angle = 90° (supplementary angles of a line segment).
Interior angle adjacent to 125° angle = 55° (supplementary angles of a line segment).
Sum of two interior angles of the triangle = 55+90 = 145°
∠p = 180° - 145° = 35°
The volume of the triangular prism is 54 cubic units.
What is the value of x?
5
9
4
3
Answer: the answer is 3
Step-by-step explanation:
I just took the test
Which of the following would increase the width of a confidence interval for a population mean? Choose the correct answer below. A. Increase the level of confidence B. Decrease the sample standard deviation. C. Increase the sample size D. All of the above
Answer:
A. Increase the level of confidence
Step-by-step explanation:
The margin of error is given by:
The margin of error is:
[tex]M = \frac{Ts}{\sqrt{n}}[/tex]
In which T is related to the level of confidence(the higher the level of confidence, the higher T is), s is the standard deviation of the sample and n is the size of the sample.
Increase the width:
That is, increasing the margin of error, as the width is twice the margin of error, the possible options are:
Increase T -> increase confidence level.
Increase s -> Increase the standard deviation of the sample.
Decrease n -> Decrease the sample size.
Thus, the correct answer is given by option A.
state and prove Bayes Theorem
Answer:
Bayes’ Theorem describes the probability of occurrence of an event related to any condition. It is also considered for the case of conditional probability.
For prove refer to the attachment.
Hope this helps you^_^
The volume of the cylinder is V=1/3r^2h, where r is the radius and h is the height. if the radius of a cylinder is 3 inches and the height is 8 inches, which answer below best estimates it’s volume?
Answer:
75 inches
Step-by-step explanation:
with this we use change of subject
V=1/3
Pie=3.14
radius =3
height =8
so therefore
V=1/3 ×3.14×3×3×8
V=75.36
Which of the following expressions are equivalent?
I. 5a6
II. 30a
III. a6 + a6 + a6 + a6 + a6
IV. 6a5
Answer:
5а⁶=а⁶+а⁶+а⁶+а⁶+а⁶
~~~~~~~~
is y=x^2 a proportional relationship?
is y=2+x a proportional relationship?
is y=2/x a proportional relationship?
is y=2x a proportional relationship?
Answer:
is y=x^2 a proportional relationship?
[tex]{ \sf{yes. \: constant \: of \: proportionality = 1}}[/tex]
is y=2+x a proportional relationship?
[tex]{ \sf{no. \: unless \: y \: is \: proportinal \: to \: (2 + x)}}[/tex]
is y=2/x a proportional relationship?
[tex]{ \sf{yes. \: where \: proportianality \: constant \: is \: 2}}[/tex]
is y=2x a proportional relationship?
[tex]{ \sf{yeah. \: constant \: is \: 2}}[/tex]
Solve. Justify your responses. Given:a║b and c║d, m∠ 4=35° Find: m∠1, m∠2, and m∠3
Answer <1 = 145
< 2= 35
<3 = 35
PLS MARK BRAINLIESTSTEPS BELOWStep-by-step explanation:
<1 + <4 = 180 (supplementary since you can find corresponding side and straight angle)
<1 = 180-35
=145 degrees
<2 =<4 corresponding angles
<2 = 35 degrees
<3 = 35 degree (corresponding to <2)
Find m∠F.
Find the answer to m∠F
Answer:
m∠F = 45°
Step-by-step explanation:
Notice the lengths of the given sides and the right angle. This is enough information to prove that this is a 45-45-90 triangle, or just basically a square cut diagonally.
Regardless if even just one side is given for a 45-45-90 triangle, all 45-45-90 triangles have one thing in common. The sides that form the right angle are equivalent and the hypotenuse is equal to one of the sides that form the right angle times the square root of two. I'm aware that it sounded confusing, as I'm awful at explaining, so just look at the picture I've attached instead of trying to understand my explanation that seemed like trying to learn a second language.
Look at the picture. See that FD = x times that square root of 2 and that DE = x. Now look back at your picture. It's connecting, now isn't it?
Now that we know that this is indeed a 45-45-90 triangle, we can confirm that m∠F = 45°
Solve for x
-3x = -15
A) x = -45
B) x = 5
C) x = -5
C-x=-5
Step-by-step explanation:
-3x=-15
or,-3x x =-15
or, x=-15÷3
therefore, x=-5
An investment of $8,120 is earning interest at the rate of 5.8% compounded quarterly over 11 years. How much
interest is earned on the investment? Show your work.
Answer:
5180.56 Dollars...........
Simplify the following expression.
(1565)
———-
(562)3
Define mean and median for a set of data
Answer:
The mean is the average number of a data set gotten by adding all the numbers then dividing by two.
the median is the middle number in a sorted set of data,either sorted in ascending order or descending order.
I hope this helps
To calculate mean:
• add up all the numbers,
• then divide by how many numbers there are.
Example:
Data: 5, 6, 10, 1
Add these all together, which is 22, then divide by 4 (because that is how many numbers there are), so:
the mean is 5.5
To calculate median:
Arrange your numbers in order.
Cross off numbers until you get to the middle.
If there is an even number of data, then find the two in the middle and find the middle of that.
Example:
Data: 5, 6, 10, 1
Arrange: 1, 5, 6, 10
So, the middle 2 are 5 and 6. In between these would be 5.5, so that is the median.
If the data was: 1, 5, 6, 8, 10,
then the median would be 6.
Click on the graph where a transformation occurred that doesn't preserve the physical characteristics of rectangle FGHI.
Answer:
Click the graph in Quadrant 1
Step-by-step explanation:
This graph is bigger in side length.
1. The lease common multiple of 3, 4, 6, and 8 is
OA. 8.
OB. 24.
O C.72.
OD.96.
Answer:
B. 24.
Step-by-step explanation:
3
4 = 2*2
6 = 2*3
8 = 2*2*2
LCM = 2*2*2*3 = 24
A drinks factory packed their drinks into red and yellow boxes. There were 24 more red boxes than yellow boxes. Each red box contained 60 packets of milk and each yellow box contained 75 packets of fruit juice. There were 120 fewer of milk than packets of fruit juice in all
boxes.
(a) How many yellow boxes were used ?
(b) How many packets of milk were packed into the the red boxes?
Answer:
A) 128
B) 7800
Step-by-step explanation:
Trial and error until I got to 75 x 104 and 60 x 128 (which abides by the fact that there has to be 24 more red boxes) which equals 7800 and 7680 and if you take them away from each other you get 120
solve: x^2-x-12÷x+5 ≥ 0
Answer:
Step-by-step explanation:
x3−x2+5x−12
x
≥0
Let's find the critical points of the inequality.
x3−x2+5x−12
x
=0
x3−x2+5x−12=0(Multiply both sides by x)
(Use cubic formula)
x=1.836169
Check possible critical points.
x=1.836169(Works in original equation)
Critical points:
x=1.836169(Makes both sides equal)
x=0(Makes left denominator equal to 0)
Check intervals in between critical points. (Test values in the intervals to see if they work.)
x<0(Works in original inequality)
0<x≤1.836169(Doesn't work in original inequality)
x≥1.836169(Works in original inequality)
Answer:
x<0 or x≥1.836169
An insurance company estimates the probability of an earthquake in the next
year to be 0.0012. The average damage done by an earthquake it estimates to be
$60,000. If the company offers earthquake insurance for $100, what is their expected
value of the policy?
Answer:
- 27.88
Step-by-step explanation:
Probability of earthquake = 0.0012
P(earthquake). = 0.0012
P(no earthquake) = 1 - p(earthquake) = 1 - 0.0012 = 0.9988
X ____ 60,000 ______ - 100
P(X) ___ 0.0012 _____ 0.9988
The expected value of the policy :
E(X) = Σx*p(x)
E(X) = (0.0012 * 60000) + (0.9988 * - 100)
E(X) = 72 - 99.88
E(X) = - 27.88
Based on the Nielsen ratings, the local CBS affiliate claims its 11:00 PM newscast reaches 41% of the viewing audience in the area. In a survey of 100 viewers, 36% indicated that they watch the late evening news on this local CBS station.Reference: 10_02What is your decision if the calculated value of z is -1.02 and the
Answer:
at 15.39% that should not be sufficient to reject the Null
= "Fail to reject the Null hypothesis"
Step-by-step explanation:
z = -1.02 (L)0.15386 (R)0.84614
84.61% / 15.39%
I need help finding what U stand for
Answer:
u = 18
Step-by-step explanation:
The two angles 3u and u+36 are equal so
3u = u+36
Subtract u from each side
3u -u = u+36-u
2u = 38
Divide by 2
2u/2 = 36/2
u = 18
can someone please help with answer and explanation
9514 1404 393
Answer:
(x, y) = (3, 12)
Step-by-step explanation:
The first step in any problem solving is to look at the problem. Here, we see that the first equation can be reduced to standard form by dividing it by 2. This would give both terms a coefficient of 1.
We see that the second equation already has a variable with a coefficient of 1.
When solving a system by substitution, it can save some effort if you start by finding a variable with a coefficient of 1 or -1. Since we see that in the second equation, we choose to solve the second equation for y:
y = 4x . . . . . . . add 4x to both sides of the second equation
Now, we have an expression for y that we can substitute into the first equation.
2x +2(4x) = 30 . . . . substitute for y
10x = 30 . . . . . . . . simplify
x = 3 . . . . . . . . . . divde by 10
y = 4(3) = 12 . . . . . find y using y=4x
The solution is (x, y) = (3, 12).
__
Additional comment
I doesn't matter what variable gets substituted. The purpose of the exercise is to reduce the number of variables in the equation. Here, we start with an equation that has 2 variables. Substituting for one of them gives an equation with only one variable, a lot easier to solve.
You don't have to find an expression for the "bare" variable. We could solve the second equation for 2x, for example: 2x = y/2, then substitute for 2x in the first equation: y/2 +2y = 30 ⇒ y = (2/5)(30) = 12. Or, we could solve the first equation for 2x and substitute into the second: 2x=30-2y, y-2(2x) = 0 ⇒ y-2(30-2y) = 0 ⇒ y = 60/5 = 12.
The substitution property of equality says you can make any substitution of equal values anywhere. "butter = margarine" means you can substitute butter for margarine, or vice versa, wherever you may wish.
Farmer Dave harvested his corn. He stored 5/9 of his corn in one large silo and ¾ of the remaining corn in a small silo. The rest was taken to market to be sold.
a. What fraction of the corn was stored in the small silo?
b. If he harvested 18 tons of corn, how many tons did he take to market?
After storing 5/9 in the large silo there was 4/9 left ( 1-5/9 = 4/9)
A. Multiply 4/9 by 3/4:
4/9 x 3/4 = 12/36 = 1/3
1/3 of the corn was in the small silo.
B. 1-5/9 -1/3 = 4/9-1/3 = 4/9-3/9 = 1/9
1/9 of the corn went to market:
18 x 1/9 = 18/9 = 2
2 ton went to market.
Find the minimum sample size needed to be 99% confident that the sample's variance is within 30% of the population's variance.
The Minimum sample size table is attached below
Answer:
[tex]X=173[/tex]
Step-by-step explanation:
From the question we are told that:
Confidence Interval [tex]CI=99\%[/tex]
Variance [tex]\sigma^2=30\%[/tex]
Generally going through the table the
Minimum sample size is
[tex]X=173[/tex]
how to find the dot product of 1×3 vectors
Answer:
Since we know the dot product of unit vectors, we can simplify the dot product formula to a⋅b=a1b1+a2b2+a3b3. we can use the same formula, but with a3=b3=0, a⋅b=a1b1+a2b2.
Step-by-step explanation:
hope it will help uplease mark me brillientA married couple had a combined annual income of $81,000. The wife made $9000 more than her husband. What was each of their incomes?
Step-by-step explanation:
Let the husband's income be x
Wife's income be x + 9000
X + X + 9000 = 81000
2X + 9000 – 9000 = 81000 – 9000
2X= 72000
X = 36000
Husband, 36000,
Wife, 9000+36000, 45000
what equation shows a slope of 2/3 and a white intercept of 0, -2
y = 2/3 x - 2
Or
y + 2 = 2/3 ( x )
Answer:
y= 2/3x - 2
hope this helps :)
