A company specializing in building robots that can clean your house has found that the average amount of time kids spend cleaning their houses is about 2 hours per week. If their sample size was 1000 randomly chosen kids and the standard deviation was 0.3 hours, what is the margin of error for a confidence interval of 95%?
Answer:
0.588
Step-by-step explanation:
Margin of error is:
ME = CV × SE
where CV is the critical value (z score or t score), and SE is the standard error (standard deviation of the sample).
Since n is large, we can approximate as a normal distribution. At 95% confidence level, z = 1.96.
Therefore, the margin of error is:
ME = 1.96 × 0.3
ME = 0.588
Using the z-distribution, it is found that the margin of error for a 95% confidence interval was of 0.0186.
What is a z-distribution confidence interval?The interval is:
[tex]\overline{x} \pm z\frac{\sigma}{\sqrt{n}}[/tex]
In which:
[tex]\overline{x}[/tex] is the sample mean.z is the critical value.n is the sample size.[tex]\sigma[/tex] is the standard deviation for the population.The margin of error is given by:
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
In this problem, we have a 95% confidence level, hence[tex]\alpha = 0.95[/tex], z is the value of Z that has a p-value of [tex]\frac{1+0.95}{2} = 0.975[/tex], so the critical value is z = 1.96.
The standard deviation for the population and the sample size are given, respectively, by:
[tex]\sigma = 0.3, n = 1000[/tex]
Hence, the margin of error is given by:
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
[tex]M = 1.96\frac{0.3}{\sqrt{1000}}[/tex]
M = 0.0186.
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COME ON ITS 1 QUESTION FOR 50 POINTS!
If you have a cubic polynomial of the form y = ax^3 + bx^2 + cx + d and lets say it passes through the points (2,28), (-1, -5), (4, 220), and (-2, -20) what would the coefficients a, b, c, and d equal? So confused, I'd greatly appreciate help! Thank you!
Answer:
a = 3
b = 2
c = 0
d = -4
Step-by-step explanation:
Form 4 equations and solve simultaneously
28 = a(2)³ + b(2)² + c(2) + d
28 = 8a + 4b + 2c + d (1)
-5 = -a + b - c + d (2)
220 = 64a + 16b + 4c + d (3)
-20 = -8a + 4b - 2c + d (4)
(1) + (4)
28 = 8a + 4b + 2c + d
-20 = -8a + 4b - 2c + d
8 = 8b + 2d
d = 4 - 4b
Equation (2)
c = -a + b + d + 5
c = -a + b + 4 - 4b+ 5
c = -a - 3b + 9
28 = 8a + 4b + 2c + d (1)
28 = 8a + 4b + 2(-a - 3b + 9) + 4 - 4b
28 = 6a - 6b + 22
6a - 6b = 6
a - b = 1
a = b + 1
220 = 64a + 16b + 4c + d (3)
220 = 64(b + 1) + 16b + 4(-b - 1 - 3b + 9) + 4 - 4b
220 = 60b + 100
60b = 120
b = 2
a = 2 + 1
a = 3
c = -3 - 3(2) + 9
c = 0
d = 4 - 4(2)
d = -4
Step-by-step explanation:
Step 1: Solve using the first point
(2, 28)
[tex]28 = a(2)^3 + b(2)^2 + c(2) + d[/tex]
[tex]28 = 8a + 4b + 2c + d[/tex]
Step 2: Solve using the second point
(-1, -5)
[tex]-5 = a(-1)^3 + b(-1)^2 + c(-1) + d[/tex]
[tex]-5 = -a + b - c + d[/tex]
Step 3: Solve using the third point
(4, 220)
[tex]220 = a(4)^3 + b(4)^2 + c(4) + d[/tex]
[tex]220 = 64a + 16b + 4c + d[/tex]
Step 4: Solve using the fourth point
(-2, -20)
[tex]-20 = a(-2)^3 + b(-2)^2 + c(-2) + d[/tex]
[tex]-20 = -8a + 4b - 2c + d[/tex]
Step 5: Combine the first and fourth equations
[tex]28 - 20 = 8a - 8a + 4b + 4b + 2c - 2c + d + d[/tex]
[tex]8 = 8b + 2d[/tex]
[tex]8 - 8b = 8b - 8b + 2d[/tex]
[tex](8 -8b)/2 = 2d/2[/tex]
[tex]4 - 4b = d[/tex]
Step 6: Solve for c in the second equation
[tex]-5 + 5 = -a + b - c + d + 5[/tex]
[tex]0 + c = -a + b - c + c + d + 5[/tex]
[tex]c = -a + b + d + 5[/tex]
Step 7: Substitute d with the stuff we got in step 5
[tex]c = -a + b + (4 - 4b) + 5[/tex]
[tex]c = -a + b + 4 - 4b + 5[/tex]
[tex]c = -a - 3b + 9[/tex]
Step 8: Substitute d and c into the first equation
[tex]28 = 8a + 4b + 2(-a - 3b + 9) + (4 - 4b)[/tex]
[tex]28 = 8a + 4b - 2a - 6b + 18 + 4 - 4b[/tex]
[tex]28 - 22 = 6a - 6b + 22 - 22[/tex]
[tex]6 / 6 = (6a - 6b) / 6[/tex]
[tex]1 + b = a - b + b[/tex]
[tex]1 + b = a[/tex]
Step 9: Substitute a, b, and c into the third equation
[tex]220 = 64(1 + b) + 16b + 4(-(1 + b) - 3b + 9) + (4 - 4b)[/tex]
[tex]220 = 64 + 64b + 16b + 4(-1 - b - 3b + 9) + 4 - 4b[/tex]
[tex]220 - 100 = 60b + 100 - 100[/tex]
[tex]120 / 60 = 60b / 60[/tex]
[tex]2 = b[/tex]
Step 10: Find a using b = 2
[tex]a = b + 1[/tex]
[tex]a = (2) + 1[/tex]
[tex]a = 3[/tex]
Step 11: Find c using a = 3 and b = 2
[tex]c = -a - 3b + 9[/tex]
[tex]c = -(3) - 3(2) + 9[/tex]
[tex]c = -3 - 6 + 9[/tex]
[tex]c = 0[/tex]
Step 12: Find d using b = 2
[tex]d = 4 - 4b[/tex]
[tex]d = 4 - 4(2)[/tex]
[tex]d = 4 - 8[/tex]
[tex]d = -4[/tex]
Answer: [tex]a = 3, b = 2, c = 0,d = -4[/tex]
I need help uwuwuwuwuwuauauuwuwuauaua
The answer is B
35+50+35+20=140
175-140= 35
3(1−2)<33
I need answers ASAP
And could u explain how to do it if possible
I will give brainliest!,
Answer:
true
Step-by-step explanation:
3(1)+3(-2)
3+(-6)=-3
-3<33 is true
please help asap, 20 points
Solving for each equation:
A: True.
[tex]\frac{n}{2} +3 *4 = \frac{n}{2}+12\\\\\frac{n}{2} + 12 = \frac{n}{2} + 12[/tex]
B: False.
[tex]\frac{1}{3}z+\frac{2}{3}z * 9 = 9z\\\\\frac{1}{3} z+6z = 9z[/tex]
C: True, given that y = 1
[tex]-8y +4.3y + 3.7 = 0\\\\-3.7y = -3.7[/tex]
D: True, given that b = 6.66667
[tex]12-1.8b+1.8b=1.8b\\12 = 1.8b[/tex]
E: True.
[tex]\frac{m}{8} + 7(\frac{m}{8} ) =m\\\\\frac{m}{8} + (\frac{7m}{8} )= m\\\\\\\frac{8m}{8} = m\\[/tex]
Help please !!! Meg correctly solves 4680 divided by 40. Enter numbers in the boxes to show the equations she could use to solve the problem.
(4000 divide )+ (600 divide
+ (80 divide)
What is 4680 divided by 40
Enter the answer in the box.
Answer:
117
Step-by-step explanation:
Here, we have to find the result when 4680 is divided by 40.
Meg wants to simplify the process of division here.
We know that 4680 can be written as 4000 + 600 + 80.
So,
[tex]4680 \div 40 = (4000 \div 40) + (600\div 40) + (80\div 40)\\\\\Rightarrow 100 + 15 + 2\\\Rightarrow 117[/tex]
This method makes division very easy if we have to find results of division for large numbers. This example is an illustration of the same.
Please refer to image attached for results.
Hence, Meg gets the result as 117.
10 points need help asap
Answer:
D
Step-by-step explanation:
It’s on probability please help
Answer:
The number of meal combinations, She has to choose:
N = 3 x 4 x 3 =36
Hope this helps!
:)
PLS HELP John’s patio needs to be re-painted.
He needs orange paint for one portion of his patio and gray paint for the other portion. Determine the total area of the patio that needs orange paint and the total area that needs gray paint. Show all calculations.
Answer:
368 square feet of orange paint.
292 square feet of grey paint.
Step-by-step explanation:
Here is a picture of my work that you can follow to show how i did it. hope this helps!
Twenty-four 4-inch wide square posts are evenly spaced with 5 feet between adjacent posts to enclose a square field, as shown. What is the outer perimeter, in feet, of the fence? Express your answer as a mixed number.
Answer:
129 1/3
Step-by-step explanation:
According to Alcumus, "There are 20 square posts which are not on a corner, so there are $20/4=5$ square posts on each side, not including the corner posts. Including the corner posts, there are 7 posts on a side, which means that there are 6 five-foot gaps between posts. Altogether the length of a side is $7\left(\frac{1}{3}\right)+6(5)=32\frac{1}{3}$ feet. The perimeter of the square is four times the side length, so the perimeter is $4\cdot 32\frac{1}{3}=\boxed{129\frac{1}{3}}$ feet."
The outer perimeter is 129 1/3 feet.
What is Unitary Method?The unitary technique involves first determining the value of a single unit, followed by the value of the necessary number of units.
For Example, Let's say Ram spends 36 Rs. for a dozen (12) bananas.
12 bananas will set you back 36 Rs. 1 banana costs 36 x 12 = 3 Rupees.
As a result, one banana costs three rupees. Let's say we need to calculate the price of 15 bananas.
This may be done as follows: 15 bananas cost 3 rupees each; 15 units cost 45 rupees.
Given:
Twenty-four 4-inch wide square posts are evenly spaced with 5 feet.
So, there are $20/4
=5$ square posts on each side, not including the corner posts.
and, including the corner posts, there are 7 posts on a side, which means that there are 6 five-foot gaps between posts.
Then, the length of a side is
= 7 1/3 + 6(5)
= 32 1/3 feet
and, The perimeter of the square
= 4 x 32 1/3
= 129 1/3 feet
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16. Use the net to find the surface area of the prism.
(1 point)
16.6 m
16.6 m
10 m
1
16.6 m
14 m
Not drawn to scale.
9 m
10 m
O276 m²
O 22 m²
O 522 m²
0968 m²
17. Find the volume of the rectangular prism. (1 point)
can you show me a picture then maybe i can help you
Hey guys I need help with this exercise can someone plz help me for 20 points?? Also write the explamation to your answer plzz!
Math problem: 13 of the same cookbooks weigh 442 grams. What is the weight of 10 of these books?
Answer:
340
Step-by-step explanation:
442 / 13 = 34
34 × 10 = 340
Answer:
340
Step-by-step explanation:
442 / 13 = 34
34 × 10 = 340
Both perpendicular lines and parallel lines must
A
never meet.
В
meet at right angles.
C
exist on the same plane.
D
be curved in the same place.
Answer:
A.) Never meet.
Step-by-step explanation:
It’s A they never meet
please help
Which two points on the number line are opposites?
A number line going from negative 2 to positive 2 in increments of 1. There are 3 equal spaces between each number. Point A is 1 mark to the right of negative 2. Point B is 1 mark to the right of negative 1. Point C is 1 mark to the right of 0. Point D is 2 marks to the right of 1.
points A and B
points B and C
points C and D
points A and D
Answer:
Its B C
Step-by-step explanation:
on edge2020
Inverse fiction of
(4/(x+2))-1
Step by step pls
Help I will mark BRAINLIEST if correct please help
Answer:
[tex](-\frac{1}{4}, \frac{5}{8} )[/tex]
Step-by-step explanation:
If you label the points on the axes, it will show that point K is actually on [tex]\frac{5}{8}[/tex] not [tex]\frac{3}{4}[/tex]
Solve 5(g-2)+g=6(g-4
Answer:
g = -13
Step-by-step explanation:
5(g-2)+g=6(g-4)
5g - 10 + g = 6g - 24
5g + g - 6g = -24 + 10
6g - 6g = -13
g = -13
Suzanne bought a sweater at the sale price of $29.99. the original cost of the seater was $49.99. what percent represents the discount they suzanne received when buying the sweater?
a: 40% discount
b: 60% discount
c: 50% discount
d: none of the above
NEED HELP ASAP MASTERY GRADE
Answer:
= 40%
Step-by-step explanation:
Original price = 100%
Discount = Op - Np = $49.99 - $29.99 = $20
If $49.99 = 100%
What about $20 = ?
= (20 x 100) ÷ 49.99
= 2000 ÷ 49.99
= 40.008
= 40%
How does knowing the absolute value of an integer help in determining the distance of two ordered pairs?
Use the grouping method to factor the polynomial below completely.
3x3 + 9x2 + 4x + 12
O A. (3.2 + 4)(x+4)
O B. (3x2+3)(x + 4)
O c. (3x2 + 4)(x+3)
O D. (3x + 3)(x+3)
Answer:
C. (3x^2+4)(x+3)
Step-by-step explanation:
3x^3+9x^2+4x+12
=(3x^3+9x^2)+(4x+12)
=3x^2(x+3)+4(x+3)
=(3x^2+4)(x+3)
Therefore, C. (3x^2+4)(x+3)
The correct factor of the polynomial is,
⇒ (x + 3) (3x² + 4)
What is an expression?Mathematical expression is defined as the collection of the numbers variables and functions by using operations like addition, subtraction, multiplication, and division.
We have to given that;
The expression is,
⇒ 3x³ + 9x² + 4x + 12
Now, We can factor the polynomial as;
⇒ 3x³ + 9x² + 4x + 12
⇒ 3x² (x + 3) + 4 (x + 3)
⇒ (x + 3) (3x² + 4)
Thus, The correct factor of the polynomial is,
⇒ (x + 3) (3x² + 4)
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Workers need to know the area of a park to determine how much grass seed to order. A worker drew a sketch of the park to find its area. Which is the area of the park?
The area of the figure is 1465 square m because the figure consists of squares and trapezoids.
What is a square?It is defined as a two-dimensional geometry that has four sides and four vertices. The sides of the square are equal in length. It is a regular quadrilateral.
We have a figure shown in the picture that represents a sketch of the park.
Workers need to know the area of a park to determine how much grass seed to order.
The figure consists of squares and trapezoids.
The trapezoid can be defined as the quadrilateral having four sides in which two sides are parallel to each other, it is a 2-dimensional geometry.
The area of the figure = area of the square + area of the trapezoid
The area of the figure = 10×10 + (38 + 40)35/2
The area of the figure = 100 + (78×35)/2
The area of the figure = 100 + 1365
The area of the figure = 1465 square m
Thus, the area of the figure is 1465 square m because the figure consists of squares and trapezoids.
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Drag the tiles to the correct boxes to complete the pairs.
Match each situation to the simulation that represents it.
Althea has to select 1 student
as the class representative
from 13 students.
Fiona is deciding which of three
forests to research for a
geography project: evergreen,
deciduous, or coniferous.
Jenny is picking a marble from
a jar with two green marbles, six
yellow marbles, and two red
marbles.
rolling a six-sided die
selecting a playing card from
the hearts suit
spinning a spinner divided into
five equal sections
Answer: rolling a six sided die☞︎Fiona forest research
Hearts suit☞︎Althea class representative
Spinner☞︎ Jenny marbles
Step-by-step explanation:
Answer:
Fiona= die
Althea=cards
Jenny=Spinner
Step-by-step explanation:
starting off Fiona has three which can evenly go into six.
Althea has 13 options which matches with the number of suits in the hearts
the Jenny would be spinner because 5 times 2 is 10
please help me out! i have a few more of these questions, about 4
Step-by-step explanation:
You can make a table of values to find the points that belong to the line and then draw the line through those points. Here are some: (-6, -2), (0, -1), and (6, 5). You can use any value for x in your table. Hope this helps!
Answer:
Step-by-step explanation:
put a point in at negative 1 first; that is the y value.
Then, go up 1 then to the right six points. that should result in the next point being at (0,6).
Keep going and draw a line
What is the range of the relation?
[(-4,3), (-4,4), (-3,1), (1,1)]
A)
{-4,-4, -3, 1}
B)
{-4, -3, 1}
C)
{1, 1, 3, 4}
D)
{1, 3, 4}
Simplify: (1 + 3i) + (7 - 2i)
Answer:
8+i
Step-by-step explanation:
Answer:
8 + 1 i
if im wrong soooooorrrrrrryyyyyy
Step-by-step explanation:
this box holds cereal. how many cubic inches of cereal can it hold the size of the box is 6 in,2 in,12 in
Please help
find the area of a trapezoid base 1 measures 20 ft base 2 messages 10 ft height measures 3 ft
Answer:
Step-by-step explanation:
(20+10)*3/2 = 45
Answer:
45 ft squared
Step-by-step explanation:
Area of a trapazoid = a plus b divuded by 2 times h
20 plus 10 divided by 2 equals 15
then 15 times 3 equals 45
5(x-10)=30-15x
Ox=1
Ox=4
Ox=5
Ox=8
Answer:
x = 4
Step-by-step explanation:
5x-50=30-15x
5x +15x =30+50
20x= 80
Divide both sides of the equation by 20
x = 4
I hope it helps
Solve this for me please
is there a picture to this??
Which equation best represents the data given in the table ?
Answer:
B
Step-by-step explanation:
The equation that satisfies the above table is y = 8[tex](\frac{1}{2})^{x}[/tex]
Given,
Table between x and y .
Here,
To get the equation between x and y first justify the data given in the table.
So,
When,
x = -3 , y = 64
x = -2 , y = 32 .
In the equation y = 8[tex](\frac{1}{2})^{x}[/tex] substitute the values of x and check for y .
Put x = -3 ,
y = 8[tex](1/2)^{-3}[/tex]
y = 8 * 8
y = 64
Thus it satisfies the value given in the table .
So the correct equation will be Option B .
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