Answer:
82
Step-by-step explanation:
A random sample of 21 desktop PCs is selected. The mean life span is 6.8 years with a standard deviation of 2.4 years. Construct a 95% confidence interval for the mean life span of all desktop PCs. Assume that the life spans of all desktop PCs are approximately normally distributed (a) (5.85, 7.75) (b) (1.68, 3.12) (c) (5.60, 8.00) (d) (5.71, 7.89) (e) (5.77, 7.83)
Answer:
(d) (5.71, 7.89)
Step-by-step explanation:
We have the standard deviation for the sample, which means that 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 = 21 - 1 = 20
95% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 20 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.95}{2} = 0.975[/tex]. So we have T = 2.086
The margin of error is:
[tex]M = T\frac{s}{\sqrt{n}} = 2.086\frac{2.4}{\sqrt{21}} = 1.09[/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 6.8 - 1.09 = 5.71 years
The upper end of the interval is the sample mean added to M. So it is 6.8 + 1.09 = 7.89 years
So the confidence interval is (5.71, 7.89), and the correct answer is given by option b.
3. What is the distance between -49 and 167?
a) -216 units
b) -118 units
c) 118 units
d) 216 units
Answer:
c) IS THE ANSWER
Step-by-step explanation:
Write the following equation in the general form Ax + By + C = 0.
y - x - 1 = 0
2x - 3y + 6 = 0
2x - 3y - 6 = 0
-2x + 3y - 6 = 0
Answer:
C. -2x +3y-6=0
this is the answer
What is the axis of symmetry for the function f(x)=7−4x+x2?
x = –3
x = –2
x = 2
x = 3
Answer:
x = 2
Step-by-step explanation:
[tex]y = {x}^{2} - 4x + 7 \\ y = (x - 2) {}^{2} - 4 + 7 \\ y = {(x - 2)}^{2} + 3[/tex]
Therefore, axis of symmetry is x = 2
The solution is: x=2, is the axis of symmetry for the function f(x)=7−4x+x2.
What is function?Function, in mathematics, an expression, rule, or law that defines a relationship between one variable (the independent variable) and another variable.
Here, we have,
f(x)=7−4x+x^2
Rewriting as
f(x) = x^2 -4x+7
a =1 b -4 c=7
The axis of symmetry is:
h = -b/2a
= -(-4)/ 2(1)
= 4/2(1)
= 4/2
=a
The axis of symmetry is x=2.
Hence, The solution is: x=2, is the axis of symmetry for the function f(x)=7−4x+x2.
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Use the formula for simple interest, I = Prt, to find the indicated quantity. Assume a 360 day year.
1 = $24; P = $1200; t = 90 days; r = ?
r=% (Simplify your answer.)
Answer:
r = 8%
Step-by-step explanation:
Given that,
Interest, I = $24
Principal, P = $1200
Time, t = 90 days = 90/360 = 1/4 years
We need to find the rate.
We know that,
The simple interest is given by :
[tex]I=\dfrac{Prt}{100}[/tex]
Put all the values,
[tex]r=\dfrac{100I}{Pt}\\\\r=\dfrac{100\times 24}{1200\times \dfrac{1}{4}}\\\\r=8\%[/tex]
So, the rate is 8%.
Pls I don’t know what to do
Answer:
[tex]{ \bf{area = \pi {r}^{2} }} \\ { \tt{ = 3.14 \times {( {8.1}) }^{2} }} \\ = { \tt{206.1 \: {cm}^{2} }}[/tex]
GUIDE QUESTIONS:
1. What is the idea or theme of the play?
2. How do you feel after watching the performance?
3. Does the integration of musical sound, songs, dialogue, and dance affect the
overall mood of the play?
Answer:
1.sowwy I dunno
2.its so good and it's perfect
3.i dunno ulet hehe
Step-by-step explanation:
Sorry walang matino na sagot.
A store decreases the price of a sofa by 16% this month only, to $5200. What was the price before the
discount
9514 1404 393
Answer:
$6190.48
Step-by-step explanation:
The price is now 1 -16% = 84% of the original price (p).
$5200 = 0.84p
p = $5200/0.84 = $6190.48
The price before the discount was $6190.48.
Pineapples are sold at 'd' cents per pound. The total weight of 3 pineapples
is 5 pounds. What is the average cost of 1 pineapple?
Answer:
(5/3)d cents exact
1.67d cents decimal approximation
Step-by-step explanation:
Average weight
5pounds/3pineapples = (5/3) pounds/pineapple
Cost of 1 pineapple
(5/3) pounds * dcents/pound
(5/3)d cents exact
1.67d cents decimal approximation
Whoever helps gets Brainliest!!! PLEASE HELP!!!
what is the x and y intercepts for y=3x-1 on a graph
Answer:
x = [tex]\frac{1}{3}[/tex] y = -1
Step-by-step explanation:
x = 0 to solve for y
[tex]y=3x-1[/tex]
[tex]y=3(0)-1[/tex]
[tex]y=-1[/tex]
y = 0 to solve for x
[tex]y=3x-1[/tex]
[tex]0=3x-1[/tex]
Add 1 to both sides
[tex]1=3x[/tex]
Divide by 3 to isolate x
[tex]\frac{1}{3} =x[/tex]
can someone give me the anwser please?
Answer:
5/6 + 11/6 = 16/ 6
Step-by-step explanation:
Distance between any Teo labeled tick marks =
(1 - 2/3) / 2 = 1/3 ÷ 2 = 1/3 * 1/2 = 1/6
From the left :
2/3 + 1/6 = 5/6
5/3 + 1/6 = 11/6
5/6 + 11/6 = (5 + 11) / 6 = 16/6
5/6 + 11/6 = 16/ 6
hello, i need help with this question
Answer:
a
Step-by-step explanation:
\lim _{x\to 0}\left(\frac{\sqrt{1+3x+x^2}-1}{\arcsin \left(2x\right)}\right)
Step-by-step explanation:
[tex]\displaystyle \lim_{x \to 0} \left(\dfrac{\sqrt{x^2 + 3x + 1} - 1}{\arcsin 2x} \right)[/tex]
Note that as [tex]x \rightarrow 0[/tex], the ratio becomes undefined. Using L'Hopital's Rule, where
[tex]\displaystyle \lim_{x \to c} \dfrac{f(x)}{g(x)} = \lim_{x \to c} \dfrac{f'(x)}{g'(x)} [/tex]
where f'(x) and g'(x) are the derivatives of the functions f(x) and g(x), respectively. Note that
[tex]f(x) = \sqrt{x^2 + 3x + 1} \:\:\text{and}\:\: g(x) = \arcsin 2x[/tex]
[tex]f'(x) = \dfrac{2x + 3}{2(\sqrt{x^2 + 3x + 1})}[/tex]
[tex]g'(x) = \dfrac{2}{\sqrt{1 - 4x^2}}[/tex]
Therefore,
[tex]\displaystyle \lim_{x \to 0} \dfrac{f'(x)}{g'(x)} = \lim_{x \to 0} \dfrac{2x + 3}{2(\sqrt{x^2 + 3x + 1})} \times \left(\dfrac{\sqrt{1 - 4x^2}}{2} \right)[/tex]
or
[tex]\displaystyle \lim_{x \to 0} \left(\dfrac{\sqrt{x^2 + 3x + 1} - 1}{\arcsin 2x} \right) = \dfrac{3}{4}[/tex]
the probability that a customer of a network operator has a problem about you needing technical staff's help in a month is 0.01. This operator installs internet for 500 households in a residential area a, Calculate the average number of households in this residential area having internet problems in a certain month
b, Calculate the probability that in 6 consecutive months there is only one month that no customer in this area has a network problem that needs the help of technical staff
Answer:
(a) average calls = 5
(b) probability that there is exactly one call in 6 consecutive monts = 0.038
Step-by-step explanation:
Let event of a customer requiring help in a particular month = H
and event of a customer not requiring help in a particular month = ~H
Given
p= 0.01, therefore
Number of households, n = 500.
Binomial distribution:
x = number of households requiring help in a particular month
P(x,n,p) = C(x,n)*p^x*(1-p)^(n-x)
where
C(x,n) = n!/(x!(n-x)!) is the the number of combinations of x objects out of n
(a) Average number of households requiring help = np = 500*0.01 = 5
(b)
Probability that there are no calls requiring help in a particular month
P(0), q= C(0,n)*p^0(1-p)^(n-0)
= 1*1*0.99^500
= 0.006570483
Applying binomial probability over six months,
q = 0.006570483
n = 6
x = 1
P(x,n,q)
= C(x,n)*q^x*(1-q)^(n-x)
= 6!/(1!*5!) * 0.006570483^1 * (1-0.006570483)^5
= 0.038145
Therefore the probability that in 6 consecutive months there is exactly one month that no customer has called for help = 0.038
The slope f '(x) at each point (x, y) on a curve. y = f (x) is given along with a particular point (a, b) on the curve. Use this information to find f (x).
[CLO-3] f '(x) = 9 x 2 + 4 x - 4; (0, -7)
By the fundamental theorem of calculus,
f(x) = f (0) + ∫₀ˣ f '(t) dt
We're given that the plot of f(x) passes through the point (0, -7), so f (0) = -7, and
f(x) = -7 + ∫₀ˣ (9t ² + 4t - 4) dt
f(x) = -7 + (3t ³ + 2t ² - 4t )|₀ˣ
f(x) = -7 + (3x ³ + 2x ² - 4x)
f(x) = 3x ³ + 2x ² - 4x - 7
The product of 7 , and a number increased by 8 , is 105. What is the number?
Answer:
97
Step-by-step explanation:
rational numbers.
Example 6: Write any 3 rational numbers between –2 and 0.
-20
0
ondas
-
Answer:
my firnd coli
Step-by-step explanation:
In a plain, robust, conversational style, the author known as “Elena Ferrante” has captivated readers worldwide with her chronicle of a complicated friendship between two women.
if three-fourth of a number is added to 14 gives result less than or equal to 20 .find the number,hense illustrate your answer on a number line
Answer:
x≤8
Step-by-step explanation:
let the number be x
¾x+14≤20
LCM=4
3x+56≤80
3x≤80-56
3x≤24
x≤8
I am unable to add number line here
Question 5(Multiple Choice Worth 1 points)
(02.04 LC)
What is the equation of a line that contains the points (2,-2) and (0, -2)?
O y = 0
Ox= -2
O y = -2
Ox=0
Sarah took the advertising department from her company on a round trip to meet with a potential client. Including Sarah a total of 14 people took the trip. She was able to purchase coach tickets for $370 and first class tickets for $1140. She used her total budget for airfare for the trip, which was $10,570. How many first class tickets did she buy? How many coach tickets did she buy?
Answer:
She bought 7 coach tickets and 7 first class tickets.
Step-by-step explanation:
1. Set the equations up using y to represent first class and x to represent coach:
x + y = 14
370x + 1140y = 10,570
2. Use a graphing calculator to graph the equations and find the point where they intersect. The intersection point will tell you the number bought:
Answer:
Sarah bought y = 8 first class tickets.
Step-by-step explanation:
You can set up a system of equations for this problem. Let x = number of coach tickets and y = number of first class tickets. Then:
330x + 1220y = 12730 (cost of coach tickets plus cost of first class tickets is total budget)
x + y = 17 (number of coach tickets plus number of first class tickets is total number of people)
Solve the second equation for y to get y = 17 - x, then plug that into the first equation and solve for x:
330x + 1220(17 - x) = 12730
330x + 20740 - 1220x = 12730
-890x + 20740 = 12730
-890x = -8010
x = 9
Sarah bought x = 9 coach tickets. Plug that into the second equation and solve for y:
9 + y = 17
y = 8
Sarah bought y = 8 first class tickets.
Hope this answer helps you :)
Have a great day
Mark brainliest
PLEASE help! I really appreciate it thanks!
Answer:
h=A-πr²÷2πr
Step-by-step explanation:
Making h subject
A=2πrh+πr²
A-πr²=2πrh
A-πr²÷2πr=h
h=A-πr²÷2πr
Answer:
The answer is [tex]h=\frac{A+-\pi r^{2} }{2\pi r}[/tex].
Step-by-step explanation:
To solve for (h), start by subtracting ([tex]\pi r^{2}[/tex]) from both sides, and the equation will look like [tex]A-\pi r^{2}= 2\pi rh+\pi r^2-\pi r^2[/tex]. The next step is to simplify the equation, which will look like [tex]A-\pi r^{2} =2\pi rh[/tex].
Next, divide both sides of the equation by [tex]2\pi r[/tex], and it will look like [tex]\frac{A-\pi r^{2} }{2\pi r} =\frac{2\pi rh}{2\pi r}[/tex]. Finally, simplify the equation, and the answer will be [tex]h=\frac{A+-\pi r^{2} }{2\pi r}[/tex].
determin 16x - 4y + 2 = 0
Answer:
16inches is your answer
Triangle ABC is translated to create triangle DFG, as shown below.
2y + 12 cm
212y - 3) cm
312x + 10) cm
12x + 12 cm
G
In these triangles, side AB is congruent to side DF, and side BC is congruent to side FG. Determine the values of x
andy
Show your work
Answer:
[tex]x=3[/tex]
[tex]y = 9[/tex]
Step-by-step explanation:
Given
The translated triangles
Required
Find x and y
We have:
[tex]AB = DF[/tex]
[tex]BC = FG[/tex]
[tex]AB = DF[/tex] means:
[tex]3(2x + 10) = 12x + 12[/tex]
Open bracket
[tex]6x + 30 = 12x + 12[/tex]
Collect like terms
[tex]12x - 6x = 30 -12[/tex]
[tex]6x = 18[/tex]
Divide by 6
[tex]x=3[/tex]
[tex]BC = FG[/tex] means
[tex]2y + 12 = 2(2y - 3)[/tex]
Open bracket
[tex]2y + 12 = 4y - 6[/tex]
Collect like terms
[tex]4y - 2y = 12+6[/tex]
[tex]2y = 18[/tex]
Divide by 2
[tex]y = 9[/tex]
pls help pls help pls help
Answer:
Step-by-step explanation:
+
= 1
Which ellipse has a major axis that is vertical?
A (x + 1)2 (y + 12)2
20
6
8 3x2 + 7y2 - 21 = 0
© An ellipse with foci (0, 15) and (0, -15) and co-vertices (4,0).and (-4, 0)
An ellipse with vertices (0, 4) and (30, 4) and co-vertices (15, 3) and (15,5)
Answer:
Step-by-step explanation:Bó tay
Find the volume of this rectangular pyramid.
Be sure to include the correct unit in your answer.
6 m
3 m
9 m
Answer:
54 m^3
Step-by-step explanation:
this is the answer = 54 m^3
Volume of the rectangular pyramid will be 54[tex]m^{3}[/tex].
What is Rectangular Pyramid?Rectangular pyramid has 5 faces where one face is rectangular which is at bases and other 4 faces are triangular which is connected at the one point .
How to calculate the volume of the rectangular pyramid?If we assume that l is the length of the base and b is the width of the base and h is height of the rectangular pyramid then we can calculate the volume of the rectangular pyramid using the formula stated below
Volume of the rectangular pyramid = V= (1/3)×l×b×h
According to the asked question
l = 6m
b = 3m
h = 9m
then we can calculate the volume of the rectangular pyramid by using the above formula
= V= (1/3)×l×b×h
= (1/3)×6m×3m×9m
= 54[tex]m^{3}[/tex]
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If f(x) is a linear function, f(−2)=4, and f(1)=−1, find an equation for f(x)
Answer:
[tex]y = -\frac{5}{3}x+\frac{2}{3}[/tex]
Step-by-step explanation:
Given
[tex]f(-2) = 4[/tex]
[tex]f(1) = -1[/tex]
Required
The equation of the function
The given parameters means that:
[tex](x_1,y_1) = (-2,4)[/tex]
[tex](x_2,y_2) = (1,-1)[/tex]
Calculate the slope (m)
[tex]m = \frac{y_2 -y_1}{x_2 -x_1}[/tex]
[tex]m = \frac{-1-4}{1--2}[/tex]
[tex]m = \frac{-5}{3}[/tex]
The equation is then calculated using:
[tex]y = m(x - x_1) + y_1[/tex]
This gives:
[tex]y =\frac{-5}{3}(x--2)+4[/tex]
[tex]y =\frac{-5}{3}(x+2)+4[/tex]
Open bracket
[tex]y = -\frac{5}{3}x-\frac{10}{3}+4[/tex]
Take LCM
[tex]y = -\frac{5}{3}x+\frac{-10+12}{3}[/tex]
[tex]y = -\frac{5}{3}x+\frac{2}{3}[/tex]
Which expression is equivalent to -6(-⅔+2x)?
O-4-12x
O-4+ 2x
O 4-12x
O 4+ 12x
Answer:
4-12x
Step-by-step explanation:
opening the brackets;
(-6×-2/3)- 12x
-2×-2 -12x
4-12x
Answer:
4 - 12x
Step-by-step explanation:
We can find an equivalent expression by distributing
-6(-⅔+2x)
Distribute by multiplying -6 times what's inside of the parenthesis ( -2/3 and 2x )
-6 * -⅔ = 4
-6 * 2x = -12x
We would be left with 4 - 12x
please help me please help me please help me
Answer:
B.50
Step-by-step explanation:
The two angles form a right angle ( indicated by the little square )
Right angles have a measure of 90 degrees
Hence, x + 10 + 30 = 90
( Note that we just created an equation that we can use to solve for x )
We now solve for x using the equation we created
x + 10 + 30 = 90
Combine like terms
x + 40 = 90
Subtract 40 from both sides
x = 50