Answer:
About 19 minutes and 50 seconds.
Step-by-step explanation:
I'm not sure but hope it helps!
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).
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
A rectangle’s perimeter is equal to 27 plus its width. The length of the rectangle is four times its width. What is the width of the rectangle in units?
Answer:
width: 3
Step-by-step explanation:
Given a length l and a width w, we can say that the perimeter is equal to
2 * l + 2 * w. Then, we also know that the perimeter is 27 plus its width, so
2 * l + 2 * w = 27 + w
and the length is 4 times its width, so length = 4 * width = l = 4 * w
We therefore have the two equations
2 * l + 2 * w = 27 + w
l = 4 * w
What we can do is plug 4* w for l in the first equation and solve from there. We thus have
2 * ( 4 * w) + 2 * w = 27 + w
8 * w + 2 * w = 27 + w
10 * w = 27 + w
subtract w from both sides to isolate the w and its coefficient
9 * w = 27
divide both sides by 9 to isolate w
w = 3
l = 4 * w = 12
Therefore, the width is 3 and the length is 12
Where are the minimum and maximum values for f(x) = -2 + 4 cos x on the interval (0,21]?
Answer:
Step-by-step explanation:
Maximum value is when cos x = 1
So it is -2 + 4(1) = 2.
Minimum value, when cos x = -1:
= -2 + 4(-1) = -6.
Answer:
The maximum 2 is reached when x=2pi,4pi, and 6pi.
The minimum -6 is reached when x=pi, 3pi,and 5pi.
Step-by-step explanation:
So let's first look at cos(x) on interval (0,21].
How many rotations is that? Does it at least contain 1 full rotation? If it contains one full rotation that means all the values from -1 to 1 (inclusive) are tagged? If it doesn't contain a full rotation, we might have to dig a little deeper.
So we know x=0 isn't included and that's when cosine is first 1,but this doesn't mean 1 won't be hit later.
Let's figure out the number of rotations:
21/(2pi)=3.3 approximately
This means we make at least 3 rotations.
So this means we definitely will have all the values from -1 to 1 tagged (inclusive).
Now let's look at whole function.
f(x) = -2 + 4 cos x
-2+(-4) to -2+4 will be the range of the function
So the minimum is -6 and the maximum is 2.
So the min occurs when cos(x)=-1 and the max occurs when cos(x)=1.
We have a little over three rotations and remember we can't include x=0.
cos(x)=1
when x=2pi (one full rotation)
when x=4pi (two full rotations)
when x=6pi (three full rotations)
We will stop here because cosine won't be 1 again until a fourth full rotation
cos(x)=-1
when x=pi (half rotation)
When x=3pi (one + half rotation)
When x=5pi (two+half rotation)
We can't include x=7pi (three+half rotation)
because this one is actually not in the interval because 3.5 is more than 3.3 .
The maximum 2 is reached when x=2pi,4pi, and 6pi.
The minimum -6 is reached when x=pi, 3pi,and 5pi.
[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
Every summer, Kendra plants a vegetable garden. Last year, she planted 6 rows of tomatoes and 8 rows of peppers. Kendra wants to keep the same ratio this year, but she only plans to plant 3 rows of tomatoes.
How many rows of peppers will Kendra plant this year?
Answer:
16
Step-by-step explanation:
hope this helps :)))))
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
help! due august 12th
If the area of a circle is 16π, the circumference of the circle is:
A. 8π
B. 16π
C. 2π
D. 4π
When two resistors with resistances of A ohms and
B ohms are in a parallel-series circuit, the total
resistance, R, in ohms, is given by the equation above.
According to this equation, which of the following
resistances of the two resistors would yield the greatest
total resistance?
A) 1 ohm and 1 ohm
B) 1 ohm and 2 ohms
C) 1 ohm and 4 ohms
D) 2 ohms and 2 ohms
Step-by-step explanation:
Answer: D) 2 ohms and 2 ohms
Use the order of operations to simplify 3/4+8(2.50-0.5).
Answer:
16[tex]\frac{3}{4}[/tex]
Step-by-step explanation:
Abdul's gas tank is 1/3 full. After he buys 12 gallons of gas, it is 7/9 full. How many gallons can abdul's tank hold
Answer:
Abdul's tank can hold 27 gallons of gas.
Step-by-step explanation:
Given that Abdul's gas tank is 1/3 full, and after he buys 12 gallons of gas, it is 7/9 full, to determine how many gallons can Abdul's tank hold the following calculation must be performed:
1/3 = 0.3333
7/9 = 0.7777
0.777 - 0.333 = 0.444
0.444 = 12
1 = X
12 / 0.444 = X
27 = X
Therefore, Abdul's tank can hold 27 gallons of gas.
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.
f x equals 1 / x - 3 + 7 find the inverse of f x and its domain
Answer:
A
Step-by-step explanation:
f(x) = 1/(x-3)+7
f(x)-7=1/(x-3)
x=1/(f(x)-7)+3
f^-1(x)=1/(x-7)+3, where x≠7
The correct answer is option (a) [tex]f^{-1}(x)= \frac{1}{x-7} +3[/tex] where [tex]x\neq 7[/tex].
DomainThe domain of a function is the complete set of possible values of the independent variable
How to find domain?Given [tex]f^{}(x)= \frac{1}{x-3} +7[/tex]
Let
[tex]y= \frac{1}{x-3} +7[/tex]
⇒y-7= 1/x-3
⇒x-3 =1/y- 7
⇒ [tex]x= \frac{1}{y-7} +3[/tex]
hence option a is correct
Learn more about domain here-brainly.com/question/24338767
#SPJ2
complete explanation please
Will mercury with a density of 13.6 g/mL float or sink?
Mercury will sink
(sorry if Im wrong)
Answer:
Sink.
Step-by-step explanation:
Mercury is a quicksilver and hence will sink.
18 is 65% of what number
Answer:
65% of 27.69 is 18.
Step-by-step explanation:
Formula = Number x 100
Percent = 18 x 100
65 = 27.69
Following shows the steps on how to derive this formula
Step 1: If 65% of a number is 18, then what is 100% of that number? Setup the equation.
18
65% = Y
100%
Step 2: Solve for Y
Using cross multiplication of two fractions, we get
65Y = 18 x 100
65Y = 1800
Y = 1800
100 = 27.69
The domain and range for function g are D(−infinity symbol, infinity symbol) and R(−infinity symbol, infinity symbol). Describe the following statement:
the limit as x approaches 3 of the function g of x equals 4
Select one:
a. The value of g at 3 is 4.
b. The value of g at 4 is 3.
c. As x gets closer to 4, the value of g gets closer to 3.
d. As x gets closer to 3, the value of g gets closer to 4.
The answer is d: As x gets closer to 3, the value of g gets closer to 4.
The limit of a function h of x as x approaches the value a, written as [tex]\lim_{x \to a} h(x) = L[/tex] is the value the function h(x) approaches as x tends to the value "a", written as x → a. In this case, L.
Given the domain and range for function g are D(−∞, ∞) and R(−∞, ∞) and that the limit as x approaches 3 of the function g of x equals 4.
This implies that as x gets closer and closer to 3, the value of g gets closer and closer to 4.
Since the value g gets closer to is 3 as x gets closer to 4, we can write that the limit as x approaches 3 of the function g of x equals 4.
we can write this as
[tex]\lim_{x \to 3} g(x) = 4[/tex]
So, as x gets closer to 3, the value of g gets closer to 4.
So, the answer is d: As x gets closer to 3, the value of g gets closer to 4.
Learn more about limits here:
https://brainly.com/question/23144996
the mean of 200 item was 50 later on it was found that two items were wrongly taken as 92 and 8 instead of 192 and 88 find the correct mean.
Answer:
Since, mean of 200 items was 50 and number of items =200
So, mean =50
Also, we know mean = number of itemssum of items
∴50=200sum of items
Sum of items = 200×50=10000
Later on, it was discovered that the two items were misread as 92 and 8 instead of 192 and 88 respectively
Then misread instead Correct item
92 192 192-92=100
8 88 88-8=80
∴ Correct sum of items =10000+180=10180
∴ Correct mean = number of items/sum of items
=10180/200 =50.9
Answer:
Hello,
203.6
Step-by-step explanation:
Sum of the item first= 50*200=10000
new sum is 10000+(192-92)+(88-8)=10180
New mean=10180/200=50.9
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
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.
What is the value of -
-X2 - 4x – 11 if x = -3?
Kirk is ordering a cheeseburger for lunch. There are 9 cheeses and 7 buns to choose from. For the sauce, Kirk has 4 options. How many different hamburgers can Kirk order if he makes exactly one selection for each option?
Answer:
252 options
Step-by-step explanation:
Please let me know if you want an explanation for why this is the answer (comment on this answer). A lot of people don't actually read the explanations, so I wouldn't want to waste my time. However, if you would like it I would be more than happy to type one out for you. Thanks!
I need help with this I will appreciate if I get an answer for this problem
Answer:
what's the problem!?......
angle CDT is the opposite angle of ADN
and the segment DF=FN, so AD= AN
and thats why angle FAN= angle FAD
here, Angle FAN =60,
therefore, FAD=60, and AFD = 90 so angle ADN must be 30 degree
and the opposite of ADN is CDT, and the opposite angles are equal.
Hope u got it.
Help me please and thank you
Step-by-step explanation:
jlejej
are u using chrome os
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.
A diamond ring was reduced from $999.99 to S789.99. Find the percent reduction in the price. Round the answer to the nearest tenth of a percent, if
necessary.
The reduction in price is?
Answer:
21%
Step-by-step explanation:
Percentage reduction is (999.99-789.99)/(999.99)=21%
3x7-12-2=7?
I have no clue please help...
Answer:
X = 28/3, or 9 1/3 or 9.3
Step-by-step explanation:
Answer:
Step-by-step explanation:
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
What is the surface area of a cube with a side length of 6 m?
156 m2
300 m2
216 m2
360 m2
Answer:
216 m²
Step-by-step explanation:
Surface area of a cube = 6a², when a = length of one side
so,
6a²
= 6×6²
= 6×36
= 216 m²
Answered by GAUTHMATH
Answer:
216 m²
Step-by-step explanation:
