Answer:
5°
Step-by-step explanation:
3w= w +10
3w-w=10
2w =10
w= 10/2
w= 5
Based on a random sample of 1140 adults, the mean amount of sleep per night is 7.96 hours. Assuming the population standard deviation for the amount of sleep per night is 1.6 hours, construct 95% confidence interval for the mean amount of sleep per night.
a. (7.67, 8.05)
b. (7.87, 8.05)
c. (8.09, 9.12)
d. (7.87, 8.23)
Answer:
at 95% confidence interval, the mean amount of sleep per night is ( 7.87, 8.05 ).
Option b) (7.87, 8.05) is the correct answer.
Step-by-step explanation:
Given the data in the question;
sample size n = 1140
sample mean x" = 7.96
standard deviation σ = 1.6
At 95% confidence interval,
significance level ∝ = 1 - 95% = 1 - 0.95 = 0.05
∝/2 = 0.05 / 2 = 0.025
Z-Critical [tex]Z_{\alpha /2[/tex] = [tex]Z_{0.025[/tex] = 1.96
Top get the Margin of error E;
E = [tex]Z_{\alpha /2[/tex] × ( σ /√n )
we substitute
E = 1.96 × ( 1.6 /√1140 )
E = 0.09
So, At 95% confidence interval of the population mean is;
⇒ x" ± E
⇒ x" - E or x" + E
we substitute
⇒ 7.96 - 0.09, 7.96 + 0.09
⇒ 7.87, 8.05
Therefore, at 95% confidence interval, the mean amount of sleep per night is ( 7.87, 8.05 ).
Option b) (7.87, 8.05) is the correct answer.
Two numbers are in the ratio 5:6. If the smaller one is decreased by 5 and
the other is increased by 3, the new ratio is 2:3. Find the number.
Answer:
Smallest Number = 35
Other Number = 42
Step-by-step explanation:
Let the smaller number be x.
Let the other number be y.
Given:
x : y = 5 : 6
That is,
[tex]\frac{x}{y} = \frac{5}{6}[/tex]
[tex]=> 5y = 6x\\\\=>x = \frac{5y}{6}[/tex]
Next: Let the smaller number be reduced by 5, x - 5
Let the other number be increased by 3, y + 3
Given : (x - 5) : (y + 3) = 2 : 3
That is,
[tex]\frac{x-5}{y+3} = \frac{2}{3}\\[/tex]
[tex](x-5) \times 3 = (y+3)\times 2\\\\substitute \ x = \frac{5y}{6}\\\\3(\frac{5y}{6} -5) = 2y + 6\\\\\frac{5y}{2} - 15 = 2y + 6\\\\\frac{5y}{2} - 2y = 6 + 15\\\\\frac{5y-4y}{2} = 21\\\\y = 21 \times 2 = 42\\\\Substitute \ y \ in \ x = \frac{5y}{6} \\\\x = \frac{5 \times 42}{6} = 35[/tex]
What is the GCF of xy3 and x3y?
Answer:
xy
Step-by-step explanation:
xy³ and x³y
GCF is xy
Answer:
I think it's xy
Step-by-step explanation:
just find the prime factors of each term
Find the surface area of the cylinder. Round your answer to the nearest tenth.
Answer:
282.74
Step-by-step explanation:
pls help im giving brainless. i need it Asap plss
An economist, an expert in the study of sales and production of goods and services, is interested in studying the average amount of money people spend, each month, on entertainment. For example, he wants to know how much people spend, each month, going to the movies, attending a concert, etc. His assistant conducted a poll of 500 randomly selected people across the country. He found a 95% confidence interval: $72 to $198. From this confidence interval the assistant concluded that people spend an average of $200 a month on entertainment. Is this a reasonable conclusion and why
Answer:
$200 is not part of the confidence interval, which means that this is not a reasonable conclusion, at the 100 - 95 = 5% level of significance.
Step-by-step explanation:
95% confidence interval: $72 to $198.
This means that we are 95% sure that the true mean spending is between $72 and $198.
From this confidence interval the assistant concluded that people spend an average of $200 a month on entertainment. Is this a reasonable conclusion and why?
$200 is not part of the confidence interval, which means that this is not a reasonable conclusion, at the 100 - 95 = 5% level of significance.
what type of information is used to obtain information on how scores are spread from the center of a distribution
Answer:
You need variability
Step-by-step explanation:
Variability measures the degree to which the scores are spread out or clustered together in a distribution.
Hope this helps:)
On their way up the hill, Jack and Jill were stopped by their parents. It seems the two of them were trying to skip out on some chores. They were told to mow the lawn, clean the kitchen, and sweep the leaves off the deck. If Jack can complete all the chores in 3 hours by himself and Jill takes only 2.25 hours to get all of it done on her own, how many minutes will it take for the two of them to get the work done together
Answer:
77.14 minutes.
Step-by-step explanation:
Jack's time = 3 hours
Jill's time = 2.25 hours = 2 1/4 = 9/4 hours
Combined time = x
Rates :
Jack = 1/3 ; jill = 1 / 2.25 = 1 / 9/4 = 4 /9
Combined rate = 1/x
Setting up the equation :
1/3 + 4/9 = 1/x
Lcm of 3 and 9 = 9
(3 + 4) / 9 = 1/x
7/9 = 1/x
Cross multiply :
7x = 9
x = 9/7 hours
x = (9/7)* 60
x = 77.14 minutes
Combined time = 77.14 minutes.
Which algebraic expression represents the phrase "seven more than half of a number"?
Answer:
Step-by-step explanation:
½X+7
find the value of x.
A 36-foot-tall tree that is leaning toward the sun casts a 40-foot-long shadow when the sun is at a
41° angle of elevation. Approximately how many degrees does the tree lean?
a. 1°
c. 4°
b. 2°
d. 7°
Answer:
64degrees
Step-by-step explanation:
Give the following
Height of tree H = 36feet
length of the shadow L = 40feeet
Requires
Angle of eleation
Using the SOH CAH TOA identity
Sin theta = opposite/hypotenuse
Sin theta = H/L
Sin theta = 36/40
SIn theta = 0.9
theta = arcsin0.9
theta = 64.16
Hence the required angle is 64degrees
Volume of Prisms and Cylinders
a. 339.12 cu. in.
b. 113.04 cu. in
c. 226.08 cu. in.
d. 1356.48 cu. in
Please select the best answer from choices provided
Answer:
A. 339.12 cu. in.
Step-by-step explanation:
I calculated it logically
please help thx 7th grade
Answer:
All of them except a trapezoid
Step-by-step explanation:
The playground has two pairs of sides that are congruent to each other (70 = 70, 50 = 50), but a trapezoid only has ONE pair of sides that are congruent to each other; the other two are not the same. Therefore, this playground can be any shape besides a trapezoid.
Expand 20 - 3 (5w+2) - 4w
14 - 19w
26 - 11w
23 + 9w
Which one ?
5 -3 over 2 x > 1 over 3
Answer:
It's true because 5-3/2 is grater than 1/3
A bag contains 5 blue, 4 red, 7 black and 2 white marbles. What is the probability of selecting a marble that is NOT white?
Answer:
8/9 (simplified)
Step-by-step explanation:
Total marbles = 18
Total of marbles not white = 16
Numerator = 16 / Denominator = 18
= 16/18
= 8/9 (simplified)
Total number of marble=18
probability of getting white marble = 2/18 =1/9
Now,
probability of not getting white marble = 1 - 1/9 = 8 / 9
The vertices of JKL are J(4,3), K(-3,4), L(-1,-1). Graph the image of JKL after a reflection in the line y=-x.
y=-x
J(-4,3)
K(3,-4)
L(1,1)
Can somebody help me with this question
Answer:
[tex]\text{a) }1,080^{\circ}, \\\text{b) }360^{\circ}, \\\text{c) }135^{\circ}, \\\text{d) }45^{\circ}[/tex]
Step-by-step explanation:
a) The sum of the interior angles of a polygon with [tex]n[/tex] sides is equal to [tex](n-2)180[/tex]. Since an octagon has 8 sides, substitute in [tex]n=8[/tex]:
[tex](6-2)180=\boxed{1,080^{\circ}}[/tex]
b) The sum of the exterior angles for any polygon is equal to [tex]360^{\circ}[/tex].
c) By definition, all regular shapes have equal angles and sides. Since we've found the total sum of the interior angles of an octagon in part a, each interior angle of a regular octagon must be [tex]\frac{1080}{8}=\boxed{135^{\circ}}[/tex]
d) Similar to part c, all regular shapes must have equal angles and sides. From part b, we know the sum of the exterior angles of a octagon is [tex]360^{\circ}[/tex], thus we have [tex]\frac{360}{8}=\boxed{45^{\circ}}[/tex]
1 point
A water tank in the form of a rectangular prism is 80 meters long and 50 meters wide. What is the volume of the water in the tank,
if the water is 40 meters deep?
Answer:
160000m³
Step-by-step explanation:
Volume of a rectangular prism= A x h
V= l x b x h
V= 80x 50 x 40
V= 160000m³
Which fraction shows a correct way to set up the slope formula for the line containing (2, -4) and (-6, 1)?
Answer:
Step-by-step explanation:
slope=y2-y1/x2-x1
here x1=2 , y1=-4 , x2=-6 , y2=1
=1-(-4)/2-(-6)
=1+4/2+6
=5/8
-5/8 fraction shows a correct way to set up the slope formula for the line containing (2, -4) and (-6, 1)
What is Slope of Line?The slope of the line is the ratio of the rise to the run, or rise divided by the run. It describes the steepness of line in the coordinate plane.
The slope intercept form of a line is y=mx+b, where m is slope and b is the y intercept.
The slope of line passing through two points (x₁, y₁) and (x₂, y₂) is
m=y₂-y₁/x₂-x₁
the slope formula for the line containing (2, -4) and (-6, 1) we calculate by plugging the values to the slope formula.
m=1-(-4)/-6-2
m=1+4/-8
m=-5/8
Hence, -5/8 fraction shows a correct way to set up the slope formula for the line containing (2, -4) and (-6, 1)
To learn more on slope of line click:
https://brainly.com/question/14511992
#SPJ2
What is the perimeter of rectangle J K L M
Step-by-step explanation:
you could count the squares around the shape or you could do it by points
For example point M is (2,3)
L is (6,3)
We want to find the length of this side so we subtract the x values
6 - 2 = 4 units
that gives use the length of that leg and since a rectangle is symmetrical, you can just measure 2 sides
pls help quicklyyy i will give 10 points pls
Answer:
[tex]0.156[/tex]
Step-by-step explanation:
[tex]15.6 \div 100[/tex]
[tex]0.156[/tex]
Hope it is helpful...hhhhhhhhelpp meeeeeee
Answer:
with what?
Step-by-step explanation:
Simplify each expression using Order of Operations.
a. 2(3 + 4) + 3 to the 3rd power
b. 5 + (3 to the 2nd power - 2 to the 2nd power)
Answer:
a) 4,913
b) 10
Step-by-step explanation:
a) [2(3 + 4) + 3]³
= [2(7) + 3]³
= (14 + 3)³
= 17³
= 4913
b) 5 + (3² - 2²)
= 5 + (9 - 4)
= 5 + 5
= 10
A tiling company completes two jobs. The first job has $1200 in labor expenses for 40 hours worked, while the second job has $1560 in labor expenses for 52 hours worked. The relationship between the labor expenses and the hours worked is linear. Which equation can be used to calculate the y-intercept of the linear equation?
Answer: 1560 = 30(52) + b
Step-by-step explanation:
Based on the information given in the question, the straight line passes through two points which are (40, 1200) and (52, 1560). Then, the equation if the straight line will be:
y - 1560 = (1200 - 1560)/(40 - 52) (x - 52)
y - 1560 = (-360)/(-12) (x - 52)
y - 1560 = 30(x - 52)
Lets put the value of x to be 0.
y - 1560 = 30(x - 52)
y - 1560 = 30(0 - 52)
y - 1560 = -30(52)
Therefore, 1560 = 30(52) + b
Which of the following shapes are polygons with more than 444 sides?
Choose 2 answers:
Choose 2 answers:
(Choice A)
A
Hexagon
(Choice B)
B
Pentagon
(Choice C)
C
Triangle
(Choice D)
D
Rectangle
Answer:
It's the hexagon and pentagon.
Similar Triangles
You are visiting the Unisphere at Flushing Meadow Park in New York. To estimate the height of the stainless steel model of Earth, you place a mirror on the ground and stand where you can see the top of the model in the mirror. The Unisphere is 100 feet from the mirror and you are standing 4 feet from the mirror. If your height is 5.6 feet, what is the estimated height of the Unisphere? The diagram is not drawn to scale.
a. 140 feet
b. 22.4 feet
c. 2,240 feet
d. 71 feet
Please select the best answer from the choices provided
Answer:
A. 140 feet
Step-by-step explanation:
I calculated it logically
Antonio is planning a birthday party for his daughter. SkateWorld charges a flat fee of $50 plus $3 per child. Roller Land charges $5 per child. If Antonio's daughter wants to invite 21 friends from school and five friends from her basketball team, which rink should Antonio use and how much would he save by doing so?
Answer:
skateworld
Step-by-step explanation:
26x3+50=128 aka skate worlds price
26x5=130 aka roller land price
Antionio should use skateworld and he would save 2$
Answer: SkateWorld. He saves $2
Step-by-step explanation:
SkateWorld:
21 *3 =63
5*3=15
63+15=78
78+50= 128
Roller Land:
21*5= 105
5*5=25
105+25=130
130-128= 2
Jeff and Eric roommates and enjoy talking about sports. They mainly discuss their favorite professional soccer teams. Jeff enjoys European soccer whereas Eric prefers American teams. Outside soccer they do not discuss much. Their lack of range of talking to it fall into which category?
0°
EXPLANATION:In each figure below find m∠1 and m∠2, if a||b. Show your work with statements.
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If you have any questions feel free to ask me^^
Have a nice and great day!
Cayler#PilipinasAngBayanKo
0°
Sana Maka help ako tnx
Topic Test
Find the surface area of a rectangular prism.
a. 2468 sq. ft.
b. 6240 sq. ft.
c. 1234 sq. ft.
d. 1844 sq. ft.
Please select the best answer from choices provided
Answer:
A. 2468 sq. ft.
Step-by-step explanation:
I calculated it logically