Answer:
The 95% confidence interval for the proportion of students who work out 4 or more times a week is (0.2432, 0.3568).
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].
In a random sample of 250 students, we found that 75 work out 4 or more times a week.
This means that [tex]n = 250, \pi = \frac{75}{250} = 0.3[/tex]
95% confidence level
So [tex]\alpha = 0.05[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].
The lower limit of this interval is:
[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.3 - 1.96\sqrt{\frac{0.3*0.7}{250}} = 0.2432[/tex]
The upper limit of this interval is:
[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.3 + 1.96\sqrt{\frac{0.3*0.7}{250}} = 0.3568[/tex]
The 95% confidence interval for the proportion of students who work out 4 or more times a week is (0.2432, 0.3568).
[tex] \frac{2}{3} \times \frac{2}{3} \times \frac{2}{3} = what[/tex]
Answer I'll make and mark as brainlist.
Answer Fast.
Post on - 2 Aug 2021
If 8 bags of chips cost 10.32;how much will you pay for 20 bags?
Answer:
$25.80
Step-by-step explanation:
First, let's find the cost of one bag of chip:
10.32/8 = 1.29
If one bag costs $1.29, simply multiply the number of bags (20) by 1.29
1.29 x 20 = 25.80
= $25.80
Answer:
25.80
Step-by-step explanation:
We can use a ratio to solve
8 bags 20 bags
------------- = ----------------
10.32 x dollars
Using cross products
8x = 10.32 * 20
8x =206.40
Divide each side by 8
8x/7 = 206.40/8
x =25.80
Use the power series method to solve the given initial-value problem. (Format your final answer as an elementary function.)
(x − 1)y'' − xy' + y = 0, y(0) = −7, y'(0) = 3
You're looking for a solution of the form
[tex]\displaystyle y = \sum_{n=0}^\infty a_n x^n[/tex]
Differentiating twice yields
[tex]\displaystyle y' = \sum_{n=0}^\infty n a_n x^{n-1} = \sum_{n=0}^\infty (n+1) a_{n+1} x^n[/tex]
[tex]\displaystyle y'' = \sum_{n=0}^\infty n(n-1) a_n x^{n-2} = \sum_{n=0}^\infty (n+1)(n+2) a_{n+2} x^n[/tex]
Substitute these series into the DE:
[tex]\displaystyle (x-1) \sum_{n=0}^\infty (n+1)(n+2) a_{n+2} x^n - x \sum_{n=0}^\infty (n+1) a_{n+1} x^n + \sum_{n=0}^\infty a_n x^n = 0[/tex]
[tex]\displaystyle \sum_{n=0}^\infty (n+1)(n+2) a_{n+2} x^{n+1} - \sum_{n=0}^\infty (n+1)(n+2) a_{n+2} x^n \\\\ \ldots \ldots \ldots - \sum_{n=0}^\infty (n+1) a_{n+1} x^{n+1} + \sum_{n=0}^\infty a_n x^n = 0[/tex]
[tex]\displaystyle \sum_{n=1}^\infty n(n+1) a_{n+1} x^n - \sum_{n=0}^\infty (n+1)(n+2) a_{n+2} x^n \\\\ \ldots \ldots \ldots - \sum_{n=1}^\infty n a_n x^n + \sum_{n=0}^\infty a_n x^n = 0[/tex]
Two of these series start with a linear term, while the other two start with a constant. Remove the constant terms of the latter two series, then condense the remaining series into one:
[tex]\displaystyle a_0-2a_2 + \sum_{n=1}^\infty \bigg(n(n+1)a_{n+1}-(n+1)(n+2)a_{n+2}-na_n+a_n\bigg) x^n = 0[/tex]
which indicates that the coefficients in the series solution are governed by the recurrence,
[tex]\begin{cases}y(0)=a_0 = -7\\y'(0)=a_1 = 3\\(n+1)(n+2)a_{n+2}-n(n+1)a_{n+1}+(n-1)a_n=0&\text{for }n\ge0\end{cases}[/tex]
Use the recurrence to get the first few coefficients:
[tex]\{a_n\}_{n\ge0} = \left\{-7,3,-\dfrac72,-\dfrac76,-\dfrac7{24},-\dfrac7{120},\ldots\right\}[/tex]
You might recognize that each coefficient in the n-th position of the list (starting at n = 0) involving a factor of -7 has a denominator resembling a factorial. Indeed,
-7 = -7/0!
-7/2 = -7/2!
-7/6 = -7/3!
and so on, with only the coefficient in the n = 1 position being the odd one out. So we have
[tex]\displaystyle y = \sum_{n=0}^\infty a_n x^n \\\\ y = -\frac7{0!} + 3x - \frac7{2!}x^2 - \frac7{3!}x^3 - \frac7{4!}x^4 + \cdots[/tex]
which looks a lot like the power series expansion for -7eˣ.
Fortunately, we can rewrite the linear term as
3x = 10x - 7x = 10x - 7/1! x
and in doing so, we can condense this solution to
[tex]\displaystyle y = 10x -\frac7{0!} - \frac7{1!}x - \frac7{2!}x^2 - \frac7{3!}x^3 - \frac7{4!}x^4 + \cdots \\\\ \boxed{y = 10x - 7e^x}[/tex]
Just to confirm this solution is valid: we have
y = 10x - 7eˣ ==> y (0) = 0 - 7 = -7
y' = 10 - 7eˣ ==> y' (0) = 10 - 7 = 3
y'' = -7eˣ
and substituting into the DE gives
-7eˣ (x - 1) - x (10 - 7eˣ ) + (10x - 7eˣ ) = 0
as required.
A capark has 34 rows and each row can acommodate 40 cars. If there are 976 cars parked, how many cars can still be parked?
Answer:
384 cars
Step-by-step explanation:
To find the total number of spaces in the carpark, we must multiply the number of rows by how many cars they can accommodate:
34 ⋅ 40 = 1360
As you can see, we have 1360 total spaces. Since there are 976 cars parked, and we want to find out how many spaces are left, we have to subtract the amount of cars parked from the total spaces.
1360 - 976 = 384
Therefore, our answer is 384, specifically, 384 cars.
Answer:
384 cars.
Step-by-step explanation:
40 * 34 - 976
= 1360 - 976
= 384.
If Damien does a job in 21 hours less time than Caitlyn, and they can do the job together in 14 hours, how
long will it take each to do the job alone?
Answer: Damien = 7.5 hours and Caitlyn = 28.5 hours
Step-by-step explanation:
Damien = X -21
Caitlyn = X
2X - 21 = 14
2X = 14 + 21
X = (14+21)/2
X = 7.5
A company wants to decrease their energy use by 17%. If their electric bill is currently $2500 a month, what will their bill be if they are successful
[tex]f(x)=e^{3x} .sinx[/tex] . tính [tex]d^{2} f(0)[/tex]
Answer:
6
Step-by-step explanation:
đạo hàm cấp 2 của f(x) rồi thế 0 vào
Hannah's suitcase has the following dimensions.
length: 27 inches
width: 21 inches
depth: 14 inches
What is the volume of Hannah's suitcase in cubic inches?
Answer:7938 inches square
Step-by-step explanation:
multiply everything
Answer:
7938
Step-by-step explanation:
Which expression is equivalent to the given expression?
Answer:
a³b
Step-by-step explanation:
(ab²)³/b⁵
= a³b⁶/b⁵
= a³b
The sum of two consecutive even integers is 54. What are the two integers?
Answer:
26 and 2
Step-by-step explanation:
Given,
Sum of two even numbers = 54
let one number be x
another number be x +2
x + x +2 = 54
2x + 2 = 54
2x = 54 - 2
2x = 52
x = 52/2
x = 26
Therefore, the numbers are 26 and 26 + 2 = 28..
What is the slope? Please Help
Answer:
-1
Step-by-step explanation:
Pick two points on the line
(0,2) and (2,0)
Using the slope formula
m = ( y2-y1)/(x2-x1)
= ( 0-2)/(2-0)
= -2/2
= -1
Answer:
-1
Step-by-step explanation:
Use two points on the line to find the slope, using rise over run.
We can use the points (0, 2) and (2, 0).
From the first point to the other, the y value decreases by 2 and the x value increases by 2.
Use rise (change in y value) over run (change in x value):
-2 / 2
= -1
So, the slope is -1.
The length of a rectangular field is 25 m more than its width. The perimeter of the field is 450 m. What is the actual width and length?
Answer:
length= 125
width= 100
Step-by-step explanation:
let width have a length of x m
therefore length= (x+25)m
perimeter=2(length +width)
p=2((x+25)+x)
p=4x+50
but we have perimeter to be 450,, we equate it to 4x+50 above,
450=4x+50
4x=400
x=100 m
length= 125
width= 100
Graph x^2/49+y+1^2/4=1
9514 1404 393
Answer:
see attached
Step-by-step explanation:
Perhaps you want a graph of ...
x^2/49 +(y +1)^2/4 = 1
This is an ellipse centered at (x, y) = (0, -1) with a major axis in the x-direction of 14, and a minor axis in the y-direction of 4.
John and mike got paid $40.00 for washing
car. John work one hour, mike worked 1.5 hrs.
How much do they get paid for time worked?
Identify the slope and y intercept of the line with equation 2y = 5x + 4
Answer:
Slope is 5/2
y-intercept is 2
Step-by-step explanation:
Turn the equation into slope intercept form [ y = mx + b ].
2y = 5x + 4
~Divide everything by 2
y = 5/2x + 2
Remember that in slope intercept form, m = slope and b = y-intercept.
Best of Luck!
Answer:
slope: 2.5
y-intercept: 2
Step-by-step explanation:
First isolate the y variable which changes the equation to y=2.5x+2
The equation of a line is mx + b where m is the slope and b and the
y-intercept. Leading us to conclude that 2.5 is the slope and 2 is the y-intercept.
Based on what we have learned, how can we ensure that we choose a sample of students that is representative of all 8:00 AM classes that take place on a given morning
Sampling technique is a way of selecting a sample from a given population. The best way to get a sample of students that represents all 8:00 AM classes is by using a stratified sampling technique.
From the complete question, we can summarize the given data as follows:
[tex]Buildings = 3[/tex] ----3 buildings in the college
[tex]Lecture\ Halls =2[/tex] ---- 2 lecture halls in each building
[tex]Capacity = 100[/tex] --- 100 students in each lecture hall
Because the students' lecture halls are not in the same building, the best way to get a sample is as follows:
Divide the students into groups (In this case, the students will be grouped by the buildings of their lecture halls)The number of students in each building is:
[tex]Students = Capacity \times Lecture\ Halls[/tex]
[tex]Students = 100 \times 2[/tex]
[tex]Students = 200[/tex]
There are 200 students in each building
Then select at random an equal proportion of student from each building (say 30 students in each building)The above method is referred to as a stratified sampling technique because the population of the students are divided into groups, before being randomly selected.
Read more about sampling techniques at:
https://brainly.com/question/9612230
Question 17 and 18 plz show ALL STEPS and HELP ME ASAP
Answer:
17) 750/9 and 18) 364
Step-by-step explanation:
17. Summation of 75*(0.1)^i from i=0 to infinity, that is equal to 75*(Summation of (0.1)^i). Summation of (0.1)^I is a geometric series with a sum of 1/(0.9)=10/9. Hence the series have a sum equal to 75*(10/9)=750/9
18) It's a series with sum=1+3+9+27+81+243=364
There is 2 questions here please help me! Thank you!
Answer:
3×(-4)×2
= -24
good day god bless you
Answer:
(−25)(5) = −125; he withdrew $125
-24
Step-by-step explanation:
Because he is withdrawing money, he is deducing money form his account, which makes the $25 negative in the equation. The weeks however, cannot be negative. so the correct answer is (−25)(5) = −125; he withdrew $125.
(3) x (-4) x (2)
(3 x -4) x (2)
(-12) x (2)
(-12 x 2)
-24
hope this helps! if you have any questions, let me know!
find the value of the trigonometric ratio
Answer:
15/17
Step-by-step explanation:
sinA = CB/CA =15/17
Answer:
15/17Step-by-step explanation:
sine = opposite / hypotenusesin A = BC/ACsin A = 15/17Find the surface area of a cube that has side length of 3.5 inches
Answer:
73.5
Step-by-step explanation:
which one of these points lies on the line described by the equation below y - 5 = 6 ( x - 7 )
Answer:
the answer would be (7,5)
HURRY plSSSSSSSSSSSSSSSSSSSSSS
What is the measure of the unknown angle?
Image of a straight angle divided into two angles. One angle is eighty degrees and the other is unknown.
Answer:
The unknown is 100
Step-by-step explanation:
A straight line is 180 degrees
We have two angles x, and 80
x+80 = 180
x = 180-80
x= 100
help whats the volume of this
Answer:
93.6
Step-by-step explanation:
The easiest way for me to complete this was to break it up into parts. I Separated the small triangle and the big triangle. I turned them both into squares and multiplied the dimensions. I then divided those by two and added them together.
16.Brendan practiced soccer for 12 hours on Monday, 1 hours on
Tuesday, 14 hours on Wednesday, and hour on Thursday in
preparation for the game on Friday. How many total hours did
Brendan practice soccer in this week
Answer:
27
Step-by-step explanation:
An electrician charges a fee of $40 plus $25 per hour. Let y be the cost in dollars of using the electrician for x hours. Choose the correct equation.
y = 40x - 25
y = 25x + 40
y = 25x - 40
y = 40x + 25
Answer:
y = 25x + 40
Step-by-step explanation:
The electrician charges $25 per hour.
The number of hours is x.
Therefore after x hours the electrician will charge $25x. (multiply the charge by the number of hours $25 * x)
Therefore fee(y) charged by the electrician = $40 + $25x
Hence y = 25x + 40
Find m<1.
33°
47°
42°
28°
Answer:
<1 = 33
Step-by-step explanation:
The sum of the angle of a triangle is 180
31+116+x = 180
x+147=180
x = 180-147
x = 33
A basketball player made 5 baskets during a game. Each basket was worth either 2 or 3 points. How many different numbers could represent the total points scored by the player?
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.
The absolute value inequality equation |2x – 1| > 3 will have what type of solution set?
Given:
The inequality is:
[tex]|2x-1|>3[/tex]
To find:
The solution set for the given inequality.
Solution:
We know that, if [tex]|x|>a[/tex], then [tex]x<-a[/tex] and [tex]x>a[/tex].
We have,
[tex]|2x-1|>3[/tex]
It can be written as:
[tex]2x-1<-3[/tex] or [tex]2x-1>3[/tex]
Case I:
[tex]2x-1<-3[/tex]
[tex]2x<-3+1[/tex]
[tex]2x<-2[/tex]
[tex]x<\dfrac{-2}{2}[/tex]
[tex]x<-1[/tex]
Case II:
[tex]2x-1>3[/tex]
[tex]2x>3+1[/tex]
[tex]2x>4[/tex]
[tex]x>\dfrac{4}{2}[/tex]
[tex]x>2[/tex]
The required solution for the given inequality is [tex]x<-1[/tex] or [tex]x>2[/tex]. The solution set in the interval notation is [tex](-\infty,-1)\cup (2,\infty)[/tex].
Therefore, the required solution set is [tex](-\infty,-1)\cup (2,\infty)[/tex].
3. Find F(3).
F(x)=-x^3+4x^2-2x
Answer:
To Find F(3) you just have to replace x=3 so:
F(3)= -3^3 + 4×3^2 -2×3 = -27 +4×9 - 6 = -33 + 36 = 3
