A certain test preparation course is designed to help students improve their scores on the LSAT exam. A mock exam is given at the beginning and end of the course to determine the effectiveness of the course. The following measurements are the net change in 6 students' scores on the exam after completing the course: 6,16,19,12,15,14.
Using these data, construct a 90% confidence interval for the average net change in a student's score after completing the course. Assume the population is approximately normal. Find the critical value that should be used in constructing the confidence interval.
Answer:
The critical value is [tex]T_c = 2.5706[/tex].
The 90% confidence interval for the average net change in a student's score after completing the course is (9.04, 18.30).
Step-by-step explanation:
Before building the confidence interval, we need to find the sample mean and the sample standard deviation:
Sample mean:
[tex]\overline{x} = \frac{6+16+19+12+15+14}{6} = 13.67[/tex]
Sample standard deviation:
[tex]s = \sqrt{\frac{(6-13.67)^2+(16-13.67)^2+(19-13.67)^2+(12-13.67)^2+(15-13.67)^2+(14-13.67)^2}{5}} = 4.4121[/tex]
Confidence interval:
We have the standard deviation for the sample, so the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 6 - 1 = 5
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 5 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.9}{2} = 0.95[/tex]. So we have T = 2.5706, that is, the critical value is [tex]T_c = 2.5706[/tex]
The margin of error is:
[tex]M = T\frac{s}{\sqrt{n}} = 2.5706\frac{4.4121}{\sqrt{6}} = 4.63[/tex]
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 13.67 - 4.63 = 9.04.
The upper end of the interval is the sample mean added to M. So it is 13.67 + 4.63 = 18.30.
The 90% confidence interval for the average net change in a student's score after completing the course is (9.04, 18.30).
simplify 27-{ 9+(12-5)÷4} with solution
Answer:
16.25
Step-by-step explanation:
first do 12 -5 = 7. then 7/4 = 1.75 then 9+1.75 = 10.75 and finally 27-10.75= 16.25
Help me please and thank you
Step-by-step explanation:
jlejej
are u using chrome os
Solve for y. 14y-6(y-3)=22
Answer:
y=0.5
Step-by-step explanation:
14y-6(y-3)=22
14y-6y+18=22
8y+18=22
8y=4
y=0.5
Then we check our work...
14(0.5)-6((0.5)-3)=22
7-6(-2.5)=22
7+15=22
7+15 does equal 22, so this solution is correct.
[tex]\sqrt{-25[/tex]
Answer:
±5i
Step-by-step explanation:
sqrt(-25)
We know that sqrt(ab) = sqrt(a) sqrt(b)
sqrt(-1) sqrt(25)
±i 5
±5i
1. In the past, Sam cashed his paycheck each month at Ready Cash, a check cashing service that
charges a 5% fee. He recently opened a checking account at Bank of America so he can now
deposit and/or cash his paycheck without a fee. If Sam is making $28,500 per year, how much will
he save by not going to Ready Cash anymore?
Step-by-step explanation:
28000 ÷ 100
=280
280 × 5
=1400
I need the answer explained
Answer:
1.33
Step-by-step explanation:
62 can only be subtracted from 82 once. So 82.46-62 would be 20.46. Since you can't subtract anymore you put a decimal point. 62x3=186 and 20.46-186=1.86 and you can subtract 186-186=0.
Please help!
The quantities x and y are proportional.
x: 4 5 10
y: 10 12.5 25
Find the constant of proportionality (r) in the equation y=rx.
9514 1404 393
Answer:
r = 2.5
Step-by-step explanation:
The constant of proportionality can be found by solving the equation for r:
r = y/x
Then any corresponding values of x and y can be used to find r:
r = 25/10 = 2.5
The constant of proportionality is 2.5.
What do these have in common
Answer:
All Equal to 0
Step-by-step explanation:
0 = 0
3 - 3 = 0
0/4 = 0
12 - 3*4 = 0
If the area of a circle is 16π, the circumference of the circle is:
A. 8π
B. 16π
C. 2π
D. 4π
Find the slope of the line
Slope=m=_____
Answer:
4
Step-by-step explanation:
Slope = y2-y1/x2-x1
We need to find two points on the graph, let's take these two points:
(x1, y1) (X2,y2)
(0,-6) and (2,2)
(2-(-6)/ (2-0) = 8/2 = 4
Answered by Gauthmath
help! due august 12th
look at the image for the quetion
Answer:
Does the answer help you?
The true length of recovery for patients with knee surgery is normally distributed with a mean of 123 days and a standard deviation of 1 day. What proportion of the patients will recover between 121 and 124 days?
Answer:
0.81859
Step-by-step explanation:
Given that the length of recovery days for patients with knee surgery is normally distributed with :
Mean, μ = 123 days
Standard deviation, σ = 1 day
The proportion of patients that will recover with 121 and 124 days :
We obtain the Probability of Z score :
Z = (x - μ) / σ
P(Z < (x - μ) / σ) < Z < P(Z < (x - μ) / σ)
P(Z < (121 - 123) / 1) < Z < P(Z < (124 - 123) / 1)
P(Z < - 2) < Z < P(Z < 1)
Using the normal distribution table :
P(Z < 1) - P(Z < - 2)
0.84134 - 0.02275
= 0.81859
An Internet company reported that its earnings will be less than the 24 cents per share that was predicted. Write an inequality showing the possible earnings per share.
Answer:
e < 24 is the inequality which shows the possible earnings per share.
Explanation:
x, will stand for the variable for earnings and less than, means it will not be higher nor the same as 24. Thus, being leaves us with one sign. The open part facing 24 means that 24 is the bigger number, therefore the smaller side represents that x has to be smaller than 24.
Answer: x<24
Step-by-step explanation:
x, will stand for the variable for earnings and less than means it will not be higher nor the same as 24. Thus being leaves us with one sign. The open part facing 24 means that 24 is the bigger number therefore the smaller side represents that x has to be smaller than 24.
Please Answer This!!! I NEEEDDD TOOO KNOWWWWW ANSWER!!!
Answer:
77.5
Step-by-step explanation:
Its rising at a constant rate between +10-15 each hour, so we if we were to add 25 or so to the 50, it would be close to 77.5, so I would assume the answer was B
The value of 4√(10) -2 is
Answer:
8√2
Step-by-step explanation:
4√(10) -2
= 4√8
=4√4×2
=4×2√2
=8√2
Madison represented the sentence "The product of 3 and the difference of and the quotient of a number and is at most 5" by using the inequality . Which best describes Madison’s error?a) The difference of –4 and the quotient of a number and –2" should be written as . b) The product of 3 and the difference of –4 and the quotient of a number and –2" should be written as . c) The less than symbol should be replaced with the less than or equal to symbol. d) The less than symbol should be replaced with the greater than symbol.
Answer:
c) The less than symbol should be replaced with the less than or equal to symbol.
Step-by-step explanation:
3(-4 - n/-2) < 5
The equation written above could be interpreted as :
The product of 3 and the difference of -4 and the quotient of a number, n and -2 is less than 5
This means that the only error in Maddison's representation is the inequality sign, the inequality sign used by Maddison is wrong.
The equation should be used with a ≤ sign and expressed thus :
3(-4 - n/-2) ≤ 5
This means the left hand side (L. H. S) is less than or equal to 5 ; this means the L. H. S is at most 5
Answer:
C
Step-by-step explanation:
Find an equation of a plane containing the line r=⟨0,4,4⟩+t⟨−3,−2,1⟩ which is parallel to the plane 1x−1y+1z=−5 in which the coefficient of x is 1.
..?.. = 0.
The plane you want is parallel to another plane, x - y + z = -5, so they share a normal vector. In this case, it's ⟨1, -1, 1⟩.
The plane must also pass through the point (0, 4, 4) since it contains r(t). Then the equation of the plane is
⟨x, y - 4, z - 4⟩ • ⟨1, -1, 1⟩ = 0
x - (y - 4) + (z - 4) = 0
x - y + z = 0
The picture shows the graphs of the movement of a pedestrian (B) and a bicyclist (A) . Using the graphs, answer the following questions:
How many times is the distance covered by the bicyclist for 1 hour greater than the distance covered by the pedestrian for the same amount of time?
Answer:
15km
Step-by-step explanation:
hope it is well understood?
Answer:
5 times.
Step-by-step explanation:
First, look at the values of each line at the 1-hour mark.
For line A (the bicyclist), the distance is about 25 km.
For line B (the pedestrian), the distance is about 5 km.
To determine how many times greater the bicyclist distance is than the pedestrian, divide the values:
[tex]\frac{25\text{km}}{5\text{km}}=5[/tex]
Therefore, the distance covered by the bicyclist for 1 hour is 5 times greater than the distance covered by the pedestrian for the same amount of time.
Operaciones con funciones Suma, resta, multiplicación y división
F(x) 6x+2
G(x) 3x-2
AYUDAAA
Answer:
let us do one night
Step-by-step explanation:
Agg-77182882
(#(+2+
Surface Area of cones
Instructions: Find the surface area of each figure. Round your answers to the nearest tenth, if necessary.
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Answer:
64.1 ft²
Step-by-step explanation:
The area of the cone is given by ...
A = πr(r +h) . . . . for radius r and slant height h
A = π(2 ft)(2 ft +8.2 ft) ≈ 64.1 ft²
I need help on this problem
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Answer:
see attached
Step-by-step explanation:
(a) The graph is scaled by a factor of 2, and shifted up 1 unit. The scaling moves each point away from the x-axis by a factor of 2. The points on the x-axis stay there. The translation moves that scaled figure up 1 unit.
__
(b) The graph is reflected across the x-axis and shifted right 4 units. The point on the x-axis stays on the x-axis.
Write the equation of the line that passes through the points (0, 4) and (- 4, - 5) . Put your answer in fully reduced slope intercept form , unless it is a vertical or horizontal line
Answer:
y=9/4x+4
Step-by-step explanation:
Start by finding the slope
m=(-5-4)/(-4-0)
m=-9/-4 = 9/4
next plug the slope and the point (-4,-5) into point slope formula
y-y1=m(x-x1)
y1=-5
x1= -4
m=9/4
y- -5 = 9/4(x - -4)
y+5=9/4(x+4)
Distribute 9/4 first
y+5=9/4x + 9
subtract 5 on both sides
y=9/4x+4
please explain it step by step
Gant Accounting performs two types of services, Audit and Tax. Gant’s overhead costs consist of computer support, $267000; and legal support, $133500. Information on the two services is:
(See screenshot)
Answer:
$240,300
Step-by-step explanation:
Given :
Overhead cost :
Computer support = $267000
legal support = $133500
Overheads applied to audit services = (Number of CPU minutes used by Audit services * activity rate per CPU minute)
+
(number of legal hours used by Audit services * activity rate per legal hour)
The overhead applied to audit is thus :
40,000 * (267,000 / (40,000 + 10,000)) +
200 * (133500 / (200 + 800)
(40000 * 5.34) + (200 * 133.5)
= $240,300
If two bags of popcorn and three drinks cost $14,
and four bags of popcorn and one drink costs
$18, how much does a drink cost?
Answer:
2dollars
Step-by-step explanation:
one bag of popcorn is 4 dollars so 4 bags of popcorn is 16 plus 1 drink which is 2 dollars equal 18.
The cost of each popcorn is $4 and the cost of each drink will be $2.
What is the solution to the equation?The allocation of weights to the important variables that produce the calculation's optimum is referred to as a direct consequence.
If two bags of popcorn and three drinks cost $14, and four bags of popcorn and one drink costs $18.
Let the cost of each popcorn be 'x' and the cost of each drink be 'y'. Then the equations are given as,
2x + 3y = 14 ...1
4x + y = 18 ...2
From equations 1 and 2, then we have
2x + 3(18 - 4x) = 14
2x + 54 - 12x = 14
10x = 40
x = $4
Then the value of the variable 'y' is calculated as,
y = 18 - 4(4)
y = 18 - 16
y = $2
The cost of each popcorn is $4 and the cost of each drink will be $2.
More about the solution of the equation link is given below.
https://brainly.com/question/545403
#SPJ2
Find the missing length indicated
Answer:
x = 960
Step-by-step explanation:
x=√{576×(576+1024)}
or, x = √(576×1600)
or, x = √576×√1600
or, x = 24×40
or, x = 960
Answered by GAUTHMATH
Answer:
Step-by-step explanation:
find the value of the trigonometric ratio. make sure to simplify the fraction if needed.
Answer:
36/39
Step-by-step explanation:
Cos(theta) = Base/Hypotenuse
Cos(X) = 36/39
Answer by formula please
Answer:
Step-by-step explanation:
I honestly have no idea what you mean by answer by formula, but I'm going to give it my best. I began by squaring both sides to get:
(a² - b²) tan²θ = b² and then distributed to get:
a² tan²θ - b² tan²θ = b² and then got the b terms on the side to get:
a² tan²θ = b² + b² tan²θ and then changed the tans to sin/cos to get:
[tex]\frac{a^2sin^2\theta}{cos^2\theta}=b^2+\frac{b^2sin^2\theta}{cos^2\theta}[/tex] and isolated the sin-squared on the left to get:
[tex]a^2sin^2\theta=cos^2\theta(b^2+\frac{b^2sin^2\theta}{cos^2\theta})[/tex] and distributed to get:
***[tex]a^2sin^2\theta=b^2cos^2\theta+b^2sin^2\theta[/tex]*** and factored the right side to get:
[tex]a^2sin^2\theta=b^2(sin^2\theta+cos^2\theta)[/tex] and utilized a trig Pythagorean identity to get:
[tex]a^2sin^2\theta=b^2(1)[/tex] and then solved for sinθ in the following way:
[tex]sin^2\theta=\frac{b^2}{a^2}[/tex] so
[tex]sin\theta=\frac{b}{a}[/tex] This, along with the *** expression above will be important. I'm picking up at the *** to solve for cosθ:
[tex]a^2sin^2\theta=b^2cos^2\theta+b^2sin^2\theta[/tex] and get the cos²θ alone on the right by subtracting to get:
[tex]a^2sin^2\theta-b^2sin^2\theta=b^2cos^2\theta[/tex] and divide by b² to get:
[tex]\frac{a^2sin^2\theta}{b^2}-sin^2\theta=cos^2\theta[/tex] and factor on the left to get:
[tex]sin^2\theta(\frac{a^2}{b^2}-1)=cos^2\theta[/tex] and take the square root of both sides to get:
[tex]\sqrt{sin^2\theta(\frac{a^2}{b^2}-1) }=cos\theta[/tex] and simplify to get:
[tex]\frac{sin\theta}{b}\sqrt{a^2-b^2}=cos\theta[/tex] and go back to the identity we found for sinθ and sub it in to get:
[tex]\frac{\frac{b}{a} }{b}\sqrt{a^2-b^2}=cos\theta[/tex] and simplifying a bit gives us:
[tex]\frac{1}{a}\sqrt{a^2-b^2}=cos\theta[/tex]
That's my spin on things....not sure if it's what you were looking for. If not.....YIKES
