Answer:
I dont Know
Step-by-step explanation:
A rectangular parcel of land has an area of 6,000 ft2. A diagonal between opposite corners is measured to be 10 ft longer than one side of the parcel. What are the dimensions of the land, correct to the nearest foot? ft (smaller value) by ft (larger value)
Answer:
50ft by 120ft
Step-by-step explanation:
Area of a rectangle = L × W
6000ft² = L × W
L = 6000/W
When a diagonal line divides a rectangle into 2 right angled triangles, the diagonal line = Hypotenuse of either of the triangle and it is the longest side.
The formula for a right angle triangle =
a² + b² = c²( c = hypotenuse)
We are told in the question that:
A diagonal between opposite corners is measured to be 10 ft longer than one side of the parcel
Let us assume the side that the hypotenuse is longer than = Width
Hence, the Diagonal = (W + 10)²
Therefore
L² + W² = (W + 10)²
Since L = 6000/W
W² + (6000/W)² = (W + 10)²
W² + (6000/W)² = (W + 10) (W + 10)
W² + (6000/W)² = W² + 10W + 10W + 100
W² + (6000/W)² = W² + 20W + 100
W² - W² + (6000/W)² = 20W+ 100
6000²/W² = 20W + 100
6000² = W²( 20W + 100)
6000² = 20W³ + 100W²
20W³ + 100W² - 6000² = 0
20W³ + 100W² - 36000000 = 0
20(W³ + 5W² - 1800000) = 0
Factorising the quadratic equation,
20(W − 120)(W² + 125W + 15000) = 0
W - 120 = 0
W = 120
Therefore,
W(Width) = 120feet
Since the Width = 120 feet
We can find the length
6000ft² = L × W
L = 6000/W
L = 6000/120
L = 50 feet
The dimensions of the land, correct to the nearest foot is 50ft by 120ft
x
Find the value
of x. Show
3
10
your work.
Step-by-step explanation:
Hello, there!!!
Let ABC be a Right angled triangle,
where, AB = 3
BC= 10
and AC= x
now,
As the triangle is a Right angled triangle, taking angle C asrefrence angle. we get,
h= AC = x
p= AB = 3
b= BC= 10
now, by Pythagoras relation we get,
[tex]h = \sqrt{ {p}^{2} + {b}^{2} } [/tex]
[tex]or ,\: h = \sqrt{ {3}^{2} + {10}^{2} } [/tex]
by simplifying it we get,
h = 10.44030
Therefore, the answer is x= 10.
Hope it helps...
Find the SURFACE AREA of the composite figure below
ASAP
Answer:
248.26 cm²
Step-by-step explanation:
Surface area of the composite figure = (surface area of cuboid + surface area of hemisphere) - 2(base area of hemisphere)
Surface area of cuboid = [tex] 2(lw + lh + hw) [/tex]
Where,
l = 10 cm
w = 5 cm
h = 4 cm
Plug in the values into the formula:
[tex] SA = 2(10*5 + 10*4 + 4*5) [/tex]
[tex] SA = 2(50 + 40 + 20) [/tex]
[tex] SA = 2(110) = 220 cm^2 [/tex]
Surface area of hemisphere = 3πr²
Where,
π = 3.14
r = 3 cm
SA of hemisphere = 3*3.14*3² = 3*3.14*9 = 84.78 cm²
Base area of hemisphere = πr²
BA = 3.14*3² = 3.14*9 = 28.26 cm²
Surface area of the composite shape = (220 + 84.78) - 2(28.26)
= 304.78 - 56.52
SA = 248.26 cm²
Find X so that m is parallel to n. Identify the postulate or theorem you used. Please help with these 3 problems, I don’t understand it at all
the corresponding angles should be equal
so, [tex] 5x+15=90 \implies 5x=75\implies x=15^{\circ}[/tex]
49, 34, and 48 students are selected from the Sophomore, Junior, and Senior classes with 496, 348, and 481 students respectively. Group of answer choices
Answer:
Stratified Random sampling.
Step-by-step explanation:
As per the scenario, It is stratified random sampling as it divides students into strata which represent Sophomores, Juniors, and Seniors.
Simple random samples of the given sizes of the proportional to the size of the stratum which is to be taken from every stratum that is to be about 10 percent of students from every class that is selected here.
Hence, according to the given situation, the correct answer is a random stratified sampling.
A box contains 40 identical discs which are either red or white if probably picking a red disc is 1/4. Calculate the number of;
1. White disc.
2. red disc that should be added such that the probability of picking a red disc will be 1/4
Determine if the matrix below is invertible. Use as few calculations as possible. Justify your answer. [Start 4 By 4 Matrix 1st Row 1st Column 4 2nd Column 5 3rd Column 7 4st Column 5 2nd Row 1st Column 0 2nd Column 1 3rd Column 4 4st Column 6 3rd Row 1st Column 0 2nd Column 0 3rd Column 3 4st Column 8 4st Row 1st Column 0 2nd Column 0 3rd Column 0 4st Column 1 EndMatrix ]
Answer:
Yes, it is invertible
Step-by-step explanation:
We need to find in the matrix determinant is different from zero, since iif it is, that the matrix is invertible.
Let's use co-factor expansion to find the determinant of this 4x4 matrix, using the column that has more zeroes in it as the co-factor, so we reduce the number of determinant calculations for the obtained sub-matrices.We pick the first column for that since it has three zeros!
Then the determinant of this matrix becomes:
[tex]4\,*Det\left[\begin{array}{ccc}1&4&6\\0&3&8\\0&0&1\end{array}\right] +0+0+0[/tex]
And the determinant of these 3x3 matrix is very simple because most of the cross multiplications render zero:
[tex]Det\left[\begin{array}{ccc}1&4&6\\0&3&8\\0&0&1\end{array}\right] =1 \,(3\,*\,1-0)+4\,(0-0)+6\,(0-0)=3[/tex]
Therefore, the Det of the initial matrix is : 4 * 3 = 12
and then the matrix is invertible
[tex]\sqrt{x+1+5=x}[/tex] Please help [tex]\sqrt{5x-x=0}[/tex] I actually can't do this, also thirty points
Answer:
It is undefined.
Step-by-step explanation:
Let's take a look at the first equation- if we simplify and move the terms, it becomes sqrt of 6 = 0, which results in an undefined value of x. The second equation works with x=0 but not the first so the value of x is undefined.
what is the end point of a ray
Answer:
point A is the rays endpoint
Step-by-step explanation:
Answer:
The "endpoint" of a ray is the origin point of the ray, or the point at which the ray starts.
Step-by-step explanation:
A ray starts at a given point, the endpoint, and then goes in a certain direction forever ad infinitum. The origin point of a ray is called "the endpoint".
Cheers.
1-What is the sum of the series? ∑j=152j Enter your answer in the box.
2-What is the sum of the series? ∑k=14(2k2−4) Enter your answer in the box.
3-What is the sum of the series? ∑k=36(2k−10)
4-Which answer represents the series in sigma notation? 1+12+14+18+116+132+164 ∑j=1712(j+1) ∑j=172j−1 ∑j=1712j+1 ∑j=17(12)j−1
5-Which answer represents the series in sigma notation? −3+(−1)+1+3+5 ∑j=155j−1 ∑j=15(3j−6) ∑j=15(2j−5) ∑j=15−3(13)j−1
Answer:
Please see the Step-by-step explanation for the answers
Step-by-step explanation:
1)
∑[tex]\left \ {{5} \atop {j=1}} \right.[/tex] 2j
The sum of series from j=1 to j=5 is:
∑ = 2(1) + 2(2) + 2(3) + 2(4) + 2(5)
= 2 + 4 + 6 + 8 + 10
∑ = 30
2)
This question is not given clearly so i assume the following series that will give you an idea how to solve this:
∑[tex]\left \ {{4} \atop {k=1}} \right.[/tex] 2k²
The sum of series from k=1 to j=4 is:
∑ = 2(1)² + 2(2)² + 2(3)² + 2(4)²
= 2(1) + 2(4) + 2(9) + 2(16)
= 2 + 8 + 18 + 32
∑ = 60
∑[tex]\left \ {{4} \atop {k=1}} \right.[/tex] (2k)²
∑ = (2*1)² + (2*2)² + (2*3)² + (2*4)²
= (2)² + (4)² + (6)² + (8)²
= 4 + 16 + 36 + 64
∑ = 120
∑[tex]\left \ {{4} \atop {k=1}} \right.[/tex] (2k)²- 4
∑ = (2*1)²-4 + (2*2)²-4 + (2*3)²-4 + (2*4)²-4
= (2)²-4 + (4)²-4 + (6)²-4 + (8)²-4
= (4-4) + (16-4) + (36-4) + (64-4)
= 0 + 12 + 32 + 60
∑ = 104
∑[tex]\left \ {{4} \atop {k=1}} \right.[/tex] 2k²- 4
∑ = 2(1)²-4 + 2(2)²-4 + 2(3)²-4 + 2(4)²-4
= 2(1)-4 + 2(4)-4 + 2(9)-4 + 2(16)-4
= (2-4) + (8-4) + (18-4) + (32-4)
= -2 + 4 + 14 + 28
∑ = 44
3)
∑[tex]\left \ {{6} \atop {k=3}} \right.[/tex] (2k-10)
∑ = (2×3−10) + (2×4−10) + (2×5−10) + (2×6−10)
= (6-10) + (8-10) + (10-10) + (12-10)
= -4 + -2 + 0 + 2
∑ = -4
4)
1+1/2+1/4+1/8+1/16+1/32+1/64
This is a geometric sequence where first term is 1 and the common ratio is 1/2 So
a = 1
This can be derived as
1/2/1 = 1/2 * 1 = 1/2
1/4/1/2 = 1/4 * 2/1 = 1/2
1/8/1/4 = 1/8 * 4/1 = 1/2
1/16/1/8 = 1/16 * 8/1 = 1/2
1/32/1/16 = 1/32 * 16/1 = 1/2
1/64/1/32 = 1/64 * 32/1 = 1/2
Hence the common ratio is r = 1/2
So n-th term is:
[tex]ar^{n-1}[/tex] = [tex]1(\frac{1}{2})^{n-1}[/tex]
So the answer that represents the series in sigma notation is:
∑[tex]\left \ {{7} \atop {j=1}} \right.[/tex] [tex](\frac{1}{2})^{j-1}[/tex]
5)
−3+(−1)+1+3+5
This is an arithmetic sequence where the first term is -3 and the common difference is 2. So
a = 1
This can be derived as
-1 - (-3) = -1 + 3 = 2
1 - (-1) = 1 + 1 = 2
3 - 1 = 2
5 - 3 = 2
Hence the common difference d = 2
The nth term is:
a + (n - 1) d
= -3 + (n−1)2
= -3 + 2(n−1)
= -3 + 2n - 2
= 2n - 5
So the answer that represents the series in sigma notation is:
∑[tex]\left \ {{5} \atop {j=1}} \right.[/tex] (2j−5)
For (1) the sum is 30, for (2) the sum is 90, for (3) the sum is -4, for(4) the sigma notation is [tex]\rm \sum j = 1(\frac{1}{2})^{j-1}\\[/tex] where j = 1 to j = 7, and for (5) the sigma notation is [tex]\rm\sum j = (2j-5)[/tex] where j = 1 to j = 5.
We have different series in the question.
It is required to find the sum of all series.
What is a series?In mathematics, a series can be defined as a group of data that followed certain rules of arithmetic.
1) We have:
[tex]\rm \sum j=2j[/tex] where j = 1 to j = 5
After expanding the series, we get:
= 2(1)+2(2)+2(3)+2(4)+2(5)
=2(1+2+3+4+5)
= 2(15)
=30
2) We have:
[tex]\rm \sum k=(2k^2-4)[/tex] where k = 1 to k = 4
After expanding the series, we get:
[tex]\rm = (2(1)^2-4)+(2(2)^2-4)+(2(3)^2-4)+(2(4)^2-4)+(2(5)^2-4)\\[/tex]
[tex]\rm = 2[1^2+2^2+3^2+4^2+5^2]-4\times5\\\\\rm=2[55]-20\\\\\rm = 90[/tex]
3) We have:
[tex]\rm \sum k= (2k-10)[/tex] where k = 3 to k = 6
After expanding the series, we get:
[tex]= (2(3)-10)+(2(4)-10)+(2(5)-10)+(2(6)-10)\\\\=2[3+4+5+6] - 10\times4\\\\=2[18] - 40\\\\= -4[/tex]
4) The series given below:
[tex]1, \frac{1}{2} ,\frac{1}{4},\frac{1}{8},\frac{1}{16},\frac{1}{32},\frac{1}{64}[/tex]
It is a geometric progression:
[tex]\rm n^t^h[/tex] for the geometric progression is given by:
[tex]\rm a_n = ar^{n-1}[/tex]
[tex]\rm a_n = 1(\frac{1}{2})^{n-1}\\\\\rm a_n = (\frac{1}{2})^{n-1}\\[/tex]
In sigma notation we can write:
[tex]\rm \sum j = 1(\frac{1}{2})^{j-1}\\[/tex] where j = 1 to j = 7
5) The given series:
−3+(−1)+1+3+5, it is arithmetic series.
[tex]\rm n^t^h[/tex] for the arithmetic progression is given by:
[tex]\rm a_n = a+(n-1)d[/tex]
[tex]\rm a_n = -3+(n-1)(2)\\\\\rm a_n = 2n-5[/tex]
In sigma notation we can write:
[tex]\rm\sum j = (2j-5)[/tex] where j = 1 to j = 5
Thus, for (1) the sum is 30, for (2) the sum is 90, for (3) the sum is -4, for(4) the sigma notation is [tex]\rm \sum j = 1(\frac{1}{2})^{j-1}\\[/tex] where j = 1 to j = 7, and for (5) the sigma notation is [tex]\rm\sum j = (2j-5)[/tex] where j = 1 to j = 5.
Learn more about the series here:
https://brainly.com/question/10813422
When x€Q, what is the solution of 3x-2/2=x-1/2 ?
Answer:
x = [tex]\frac{1}{2}[/tex]
Step-by-step explanation:
[tex]\frac{3x-2}{2}[/tex] = [tex]\frac{x-1}{2}[/tex]
Cross-multiply:
2(3x-2) = 2(x-1)
Simplify:
6x - 4 = 2x - 2
Subtract 2x from both sides:
4x - 4 = -2
Add 4 to both sides:
4x = 2
Divide both sides by 4:
x = [tex]\frac{1}{2}[/tex]
Let A = {June, Janet, Jill, Justin, Jeffrey, Jelly}, B = {Janet, Jelly, Justin}, and C = {Irina, Irena, Arena, Arina, Jelly}. Find the given set. A ∪ C a. {June, Janet, Jill, Justin, Jeffrey, Jelly, Irina, Irena, Arena, Arina} b. {June, Justin, Irina, Irena, Arena, Arina, Jelly} c. {June, Janet, Jill, Justin, June, Jelly} {Jelly} d. ∅
Answer:
{June, Janet, Jill, Justin, Jeffrey, Jelly,Irina, Irena, Arena, Arina, }
Step-by-step explanation:
A ∪ C
This means union so we join the sets together
A = {June, Janet, Jill, Justin, Jeffrey, Jelly} + C = {Irina, Irena, Arena, Arina, Jelly}
A U C = {June, Janet, Jill, Justin, Jeffrey, Jelly,Irina, Irena, Arena, Arina, Jelly}
We get rid of repeats
A U C = {June, Janet, Jill, Justin, Jeffrey, Jelly,Irina, Irena, Arena, Arina, }
Calculate two iterations of Newton's Method for the function using the given initial guess. (Round your answers to four decimal places.) f(x) = x2 − 5, x1 = 2n xn f(xn) f '(xn) f(xn)/f '(xn) xn − f(xn)/f '(xn)1 2
Answer:
Step-by-step explanation:
Given that:
[tex]\mathsf{f(x) = x^2 -5 } \\ \\ \mathsf{x_1 = 2}[/tex]
The derivative of the first function of (x) is:
[tex]\mathsf{f'(x) =2x }[/tex]
According to Newton's Raphson method for function formula:
[tex]{\mathrm{x_{n+1} = x_n - \dfrac{f(x_n)}{f'(x_n)}}[/tex]
where;
[tex]\mathbf{x_1 =2}[/tex]
The first iteration is as follows:
[tex]\mathtt{f(x_1) = (2)^2 - 5} \\ \\ \mathbf{f(x_1) = -1}[/tex]
[tex]\mathtt{f'(x_1) = 2(2)} \\ \\ \mathbf{ = 4}[/tex]
[tex]\mathtt{\dfrac{f(x_1)}{f'(x_1)}} = \dfrac{-1}{4}}[/tex]
[tex]\mathbf{\dfrac{f(x_1)}{f'(x_1)} =-0.25}[/tex]
[tex]\mathtt{x_1 - \dfrac{f(x_1)}{f'(x_1)}} = \mathtt{2 - (-0.25)}}[/tex]
[tex]\mathbf{x_1 - \dfrac{f(x_1)}{f'(x_1)} = 2.25}[/tex]
Therefore;
[tex]\mathbf{x_2 = 2.25}[/tex]
For the second iteration;
[tex]\mathtt f(x_2) = (2.25)^2 -5}[/tex]
[tex]\mathtt f(x_2) = 5.0625-5}[/tex]
[tex]\mathbf{ f(x_2) =0.0625}[/tex]
[tex]\mathtt{f'(x_2)= 2(2.25)}[/tex]
[tex]\mathbf{f'(x_2)= 4.5}[/tex]
[tex]\mathtt{ \dfrac{f(x_2)}{f'(x_2)}} = \dfrac{0.0625}{4.5}}[/tex]
[tex]\mathbf{ \dfrac{f(x_2)}{f'(x_2)} = 0.01389}[/tex]
[tex]\mathtt{x_2 - \dfrac{f(x_2)}{f'(x_2)}} = \mathtt{2.25 -0.01389}}[/tex]
[tex]\mathbf{x_2 - \dfrac{f(x_2)}{f'(x_2)} = 2.2361}}[/tex]
Therefore, [tex]\mathbf{x_3 = 2.2361}[/tex]
There are 937 entries for a talent show.
What is the value of the 3?
Answer:
the value of the 3 is 30
Step-by-step explanation:
the second digit to the left of a decimal is always tens column
Karmen returned a bicycle to Earl's Bike Shop. The sales receipt showed a total paid price of $211.86, including the 7% sales tax. What was the cost of the bicycle without the sales tax? Any help would be very appreciated! Thank you very much!
Answer:
$198
Step-by-step explanation:
198x.07=13.86
198+13.86=211.86
Can someone explain to me what a “derivative” means? How do you find the derivative of f(x)=x^3+1?
Please answer this correctly without making mistakes I need to finish this today as soon as possible
Answer:
14 miles
Step-by-step explanation:
Since we know that the distance of the paths from Cedarburg to Allenville is 22 and 13/16 miles, and we know the distance from Cedarburg to Lakeside is 8 and 13/16 miles.
We know that the total distance is made up of the distance from C to L and L to A.
So 22 and 13/16 = 8 and 13/16 + L to A
We can subtract 22 and 13/16 by 8 and 13/16 to get 14 miles.
Hope this helps.
Need a little help thanks :D
Answer:
71°
Step-by-step explanation:
Consider triangle BDH. x is the external angle that is remote to internal angles B and D, so is equal to their sum:
x° = 41° +30°
x° = 71°
Evaluate 2/3 + 1/3 + 1/6 + … THIS IS CONTINUOUS. It is NOT as simple as 2/3 + 1/3 + 1/6.
[tex]a=\dfrac{2}{3}\\r=\dfrac{1}{2}[/tex]
The sum exists if [tex]|r|<1[/tex]
[tex]\left|\dfrac{1}{2}\right|<1[/tex] therefore the sum exists
[tex]\displaystyle\\\sum_{k=0}^{\infty}ar^k=\dfrac{a}{1-r}[/tex]
[tex]\dfrac{2}{3}+\dfrac{1}{3}+\dfrac{1}{6}+\ldots=\dfrac{\dfrac{2}{3}}{1-\dfrac{1}{2}}=\dfrac{\dfrac{2}{3}}{\dfrac{1}{2}}=\dfrac{2}{3}\cdot 2=\dfrac{4}{3}[/tex]
graph 3x-y-2=0 using the x- and y-intercepts
Step-by-step explanation:
I used an app called DESMOS It Is usually super helpful!!!
Solve for y: 1/3y+4=16
Hey there! I'm happy to help!
We want to isolate y on one side of the equation to see what it equals. To do this, we use inverse operations to cancel out numbers on the y side and find the correct value.
1/3y+4=16
We subtract 4 from both sides, canceling out the +4 on the right but keeping the same y-value by doing the same to the other side.
1/3y=12
We divide both sides by 1/3 (which is multiplying both sides by 3) which will cancel out the 1/3 and tell us what y is equal to.
y=36
Now you know how to solve basic equations! Have a wonderful day! :D
a) which function has the graph with the greatest slope?
b) which functions have graphs with y intercepts greater than 3?
c)which function has the graph with a y intercept closest to 0
Answer:
a). Function (4)
b). Function (2)
c). Function (3)
Step-by-step explanation:
Characteristics of the functions given,
Function (1),
Form the given graph,
Slope = [tex]\frac{\text{Rise}}{\text{Run}}[/tex]
= [tex]-\frac{4}{1}[/tex]
= -4
Y- intercept of the given function = 2
Function (2),
From he given table,
Slope = [tex]\frac{y_2-y_1}{x_2-x_1}[/tex]
= [tex]\frac{5-3}{0+1}[/tex]
= 2
y-intercept = 5 [Value of y for x = 0]
Function (3),
y = -x - 1
By comparing this equation with y = mx + b
Where 'm' = slope
and b = y-intercept
Slope = (-1)
y-intercept = (-1)
Function (4),
Slope = 5
y-intercept = (-4)
(a). Greatest slope of the function → Function (4)
(b). y-intercept greater than 3 → Function (2)
(c). Function with y-intercept closest to 0 → Function (3)
The ratio of the number of Anne's pencils to the number of jason's pencils is 4:3 Anne has 100 pencils how many pencils does jason have
Answer:
75
Step-by-step explanation:
4:3
4x25=100
3x25=75
A bag contains 6 red marbles, 3 blue marbles and 1 green marble. What is the probability that a randomly selected marble is not blue?
Answer:
3/10
Step-by-step explanation:
6+3+1=10
since there are 3 blue marbles, we put the 3 into the place of the numerator
and since there is 10 marbles in total it goes into the denominator
The probability that a randomly selected marble is not blue will be 0.70.
What is probability?Its basic premise is that something will almost certainly happen. The percentage of favorable events to the total number of occurrences.
A bag contains 6 red marbles, 3 blue marbles and 1 green marble.
The total number of the event will be
Total event = 6 + 3 + 1
Total event = 10
Then the probability that a randomly selected marble is not blue will be
Favorable event = 7 {red, green}
Then the probability will be
P = 7 / 10
P = 0.70
More about the probability link is given below.
https://brainly.com/question/795909
#SPJ2
which of the following are possible values of r?
[tex] {r}^{2 } = \frac{3}{16} [/tex]
Answer:
[tex]r=\frac{\sqrt{3} }{4}[/tex] and [tex]r=-\frac{\sqrt{3} }{4}[/tex]
Step-by-step explanation:
when you solve for r in the given equation, you need to apply the square root property, which gives positive and negative answers (both should therefore be considered):
[tex]r^2=\frac{3}{16} \\r=+/-\sqrt{\frac{3}{16}} \\r=+/-\frac{\sqrt{3} }{4}[/tex]
then you need to include these two possible solutions:
[tex]r=\frac{\sqrt{3} }{4}[/tex] and [tex]r=-\frac{\sqrt{3} }{4}[/tex]
The amount of money spent on textbooks per year for students is approximately normal.
A. To estimate the population mean, 19 students are randomly selected the sample mean was $390 and the standard deviation was $120. Find a 95% confidence for the population meam.
B. If the confidence level in part a changed from 95% 1 to 1999%, would the margin of error for the confidence interval:
1. decrease.
2. stay the same.
3. increase not.
C. If the sample size in part a changed from 19% 10 to 22, would the margin of errot for the confidence interval:
1. decrease.
2. stay the same.
3. increase
D. To estimate the proportion of students who purchase their textbookslused, 500 students were sampled. 210 of these students purchased used textbooks. Find a 99% confidence interval for the proportion of students who purchase used text books.
Answer:
(A) A 95% confidence for the population mean is [$332.16, $447.84] .
(B) If the confidence level in part (a) changed from 95% to 99%, then the margin of error for the confidence interval would increase.
(C) If the sample size in part (a) changed from 19 to 22, then the margin of error for the confidence interval would decrease.
(D) A 99% confidence interval for the proportion of students who purchase used textbooks is [0.363, 0.477] .
Step-by-step explanation:
We are given that 19 students are randomly selected the sample mean was $390 and the standard deviation was $120.
Firstly, the pivotal quantity for finding the confidence interval for the population mean is given by;
P.Q. = [tex]\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }[/tex] ~ [tex]t_n_-_1[/tex]
where, [tex]\bar X[/tex] = sample mean = $390
s = sample standard deviation = $120
n = sample of students = 19
[tex]\mu[/tex] = population mean
Here for constructing a 95% confidence interval we have used a One-sample t-test statistics because we don't know about population standard deviation.
So, 95% confidence interval for the population mean, [tex]\mu[/tex] is ;
P(-2.101 < [tex]t_1_8[/tex] < 2.101) = 0.95 {As the critical value of t at 18 degrees of
freedom are -2.101 & 2.101 with P = 2.5%}
P(-2.101 < [tex]\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }[/tex] < 2.101) = 0.95
P( [tex]-2.101 \times {\frac{s}{\sqrt{n} } }[/tex] < [tex]{\bar X-\mu}[/tex] < [tex]2.101 \times {\frac{s}{\sqrt{n} } }[/tex] ) = 0.95
P( [tex]\bar X-2.101 \times {\frac{s}{\sqrt{n} } }[/tex] < [tex]\mu[/tex] < [tex]\bar X+2.101 \times {\frac{s}{\sqrt{n} } }[/tex] ) = 0.95
95% confidence interval for [tex]\mu[/tex] = [ [tex]\bar X-2.101 \times {\frac{s}{\sqrt{n} } }[/tex] , [tex]\bar X+2.101 \times {\frac{s}{\sqrt{n} } }[/tex] ]
= [ [tex]\$390-2.101 \times {\frac{\$120}{\sqrt{19} } }[/tex] , [tex]\$390+2.101 \times {\frac{\$120}{\sqrt{19} } }[/tex] ]
= [$332.16, $447.84]
(A) Therefore, a 95% confidence for the population mean is [$332.16, $447.84] .
(B) If the confidence level in part (a) changed from 95% to 99%, then the margin of error for the confidence interval which is [tex]Z_(_\frac{\alpha}{2}_) \times \frac{s}{\sqrt{n} }[/tex] would increase because of an increase in the z value.
(C) If the sample size in part (a) changed from 19 to 22, then the margin of error for the confidence interval which is [tex]Z_(_\frac{\alpha}{2}_) \times \frac{s}{\sqrt{n} }[/tex] would decrease because as denominator increases; the whole fraction decreases.
(D) We are given that to estimate the proportion of students who purchase their textbooks used, 500 students were sampled. 210 of these students purchased used textbooks.
Firstly, the pivotal quantity for finding the confidence interval for the population proportion is given by;
P.Q. = [tex]\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] ~ N(0,1)
where, [tex]\hat p[/tex] = sample proportion students who purchase their used textbooks = [tex]\frac{210}{500}[/tex] = 0.42
n = sample of students = 500
p = population proportion
Here for constructing a 99% confidence interval we have used a One-sample z-test statistics for proportions
So, 99% confidence interval for the population proportion, p is ;
P(-2.58 < N(0,1) < 2.58) = 0.99 {As the critical value of z at 0.5%
level of significance are -2.58 & 2.58}
P(-2.58 < [tex]\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] < 2.58) = 0.99
P( [tex]-2.58 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] < [tex]{\hat p-p}[/tex] < [tex]2.58 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] ) = 0.99
P( [tex]\hat p-2.58 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] < p < [tex]\hat p+2.58 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] ) = 0.99
99% confidence interval for p = [ [tex]\hat p-2.58 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] , [tex]\hat p+2.58 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] ]
= [ [tex]0.42 -2.58 \times {\sqrt{\frac{0.42(1-0.42)}{500} } }[/tex] , [tex]0.42 +2.58 \times {\sqrt{\frac{0.42(1-0.42)}{500} } }[/tex] ]
= [0.363, 0.477]
Therefore, a 99% confidence interval for the proportion of students who purchase used textbooks is [0.363, 0.477] .
pls answer my question please
Bold = changed words
1. We play tennis every Sunday.
2. I own two dogs and a cat. I love animals.
3. My suitcase weighs four kilos (kilograms).
4. When Mary came in, I talked to my mother on the phone. OR: I talked to Mother on the phone when Mary came in.
5. We passed the hotel two minutes ago. OR: We passed by the hotel two minutes ago.
Find the smallest positive integer that satisfies both of the following equations: = 3 (mod4) and = 5 (mod6)
Answer:
x=3mod4
Means that when x is divided by 4 it gives an unknown integer and a remainder of 3.
x/4 = Z + 3/4
Z= (x-3)/4
Where Z is the integer
x=5 mod6
x/6 = Y + 5/6
Y = (x-5)/6
Where Y is the integer
Z-Y must be an integer on equal to zero
(x-3)/4 - (x-5)/6
3(x-3)/12 - 2(x-5)/12
(3x-9-2x+10)/12
(x+1)/12
If it is equal to 0
x=-1. But x should be positive
If it is equal to 1
x=11
Hence the smallest possible number is 11
line and passes through C -2,0 in the 1, -3) Quetion of the line in standard form
Answer:
[tex]\huge\boxed{x+y=-2}[/tex]
Step-by-step explanation:
The standard form of an equation of a line:
[tex]Ax+By=C[/tex]
The point-slope form of an equation of a line:
[tex]y-y_1=m(x-x_1)[/tex]
where
[tex]m=\dfrac{y_2-y_1}{x_2-x_1}[/tex]
We have two points (-2, 0) and (1, -3).
Substitute:
[tex]x_1=-2;\ y_1=0;\ x_2=1;\ y_2=-3[/tex]
[tex]m=\dfrac{-3-0}{1-(-2)}=\dfrac{-3}{1+2}=\dfrac{-3}{3}=-1\\\\y-0=-1(x-(-2))\\\\y=-(x+2)[/tex]
[tex]y=-x-2[/tex] add x to both sides
[tex]x+y=-2[/tex]
In a study of 24 criminals convicted of antitrust offenses, the average age was 60 years, with a standard deviation of 7.4 years. Construct a 95% confidence interval on the true mean age. (Give your answers correct to one decimal place.)___ to____ years
Answer: 56.9 years to 63.1 years.
Step-by-step explanation:
Confidence interval for population mean (when population standard deviation is unknown):
[tex]\overline{x}\pm t_{\alpha/2}{\dfrac{s}{\sqrt{n}}}[/tex]
, where [tex]\overline{x}[/tex]= sample mean, n= sample size, s= sample standard deviation, [tex]t_{\alpha/2}[/tex]= Two tailed t-value for [tex]\alpha[/tex].
Given: n= 24
degree of freedom = n- 1= 23
[tex]\overline{x}[/tex]= 60 years
s= 7.4 years
[tex]\alpha=0.05[/tex]
Two tailed t-critical value for significance level of [tex]\alpha=0.05[/tex] and degree of freedom 23:
[tex]t_{\alpha/2}=2.0687[/tex]
A 95% confidence interval on the true mean age:
[tex]60\pm (2.0686){\dfrac{7.4}{\sqrt{24}}}\\\\\approx60\pm3.1\\\\=(60-3.1,\ 60+3.1)\\\\=(56.9,\ 63.1)[/tex]
Hence, a 95% confidence interval on the true mean age. : 56.9 years to 63.1 years.
