Answer:
(A) The shape of the distribution of the sample mean is bell-shaped.
(B) The standard error of the distribution of the sample mean is 1.1.
(C) The proportion of the samples that have a mean useful life of more than 36 hours is 0.1814.
(D) The proportion of the sample that has a mean useful life greater than 34.5 hours is 0.6736.
(E) The proportion of the sample that has a mean useful life between 34.5 and 36.0 hours is 0.4922.
Step-by-step explanation:
We are given that Power +, Inc. produces AA batteries used in remote-controlled toy cars. The mean life of these batteries follows the normal probability distribution with a mean of 35.0 hours and a standard deviation of 5.5 hours.
As a part of its quality assurance program, Power +, Inc. tests samples of 25 batteries.
Let [tex]\bar X[/tex] = sample mean life of these batteries
(A) The shape of the distribution of the sample mean will be bell-shaped because the sample mean also follows the normal distribution as it is taken from the population data only.
(B) The standard error of the distribution of the sample mean is given by;
Standard error = [tex]\frac{\sigma}{\sqrt{n} }[/tex]
Here, [tex]\sigma[/tex] = standard deviation = 5.5 hours
n = sample of batteries = 25
So, the standard error = [tex]\frac{5.5}{\sqrt{25} }[/tex] = 1.1.
(C) The z-score probability distribution for the sample mean is given by;
Z = [tex]\frac{\bar X - \mu}{\frac{\sigma}{\sqrt{n} } }[/tex] ~ N(0,1)
where, [tex]\mu[/tex] = population mean life of battery = 35.0 hours
[tex]\sigma[/tex] = standard deviation = 5.5 hours
n = sample of batteries = 25
Now, the proportion of the samples that will have a mean useful life of more than 36 hours is given by = P([tex]\bar X[/tex] > 36 hours)
P([tex]\bar X[/tex] > 36 hours) = P( [tex]\frac{\bar X - \mu}{\frac{\sigma}{\sqrt{n} } }[/tex] > [tex]\frac{36-35}{\frac{5.5}{\sqrt{25} } }[/tex] ) = P(Z > 0.91) = 1 - P(Z [tex]\leq[/tex] 0.91)
= 1 - 0.8186 = 0.1814
(D) The proportion of the samples that will have a mean useful life of more than 34.5 hours is given by = P([tex]\bar X[/tex] > 34.5 hours)
P([tex]\bar X[/tex] > 34.5 hours) = P( [tex]\frac{\bar X - \mu}{\frac{\sigma}{\sqrt{n} } }[/tex] > [tex]\frac{34.5-35}{\frac{5.5}{\sqrt{25} } }[/tex] ) = P(Z > -0.45) = P(Z [tex]\leq[/tex] 0.45)
= 0.6736
(E) The proportion of the samples that will have a mean useful life between 34.5 and 36.0 hours is given by = P(34.5 hrs < [tex]\bar X[/tex] > 36 hrs)
P(34.5 hrs < [tex]\bar X[/tex] < 36 hrs) = P([tex]\bar X[/tex] < 36 hrs) - P([tex]\bar X[/tex] [tex]\leq[/tex] 34.5 hrs)
P([tex]\bar X[/tex] < 36 hours) = P( [tex]\frac{\bar X - \mu}{\frac{\sigma}{\sqrt{n} } }[/tex] < [tex]\frac{36-35}{\frac{5.5}{\sqrt{25} } }[/tex] ) = P(Z < 0.91) = 0.8186
P([tex]\bar X[/tex] [tex]\leq[/tex] 34.5 hours) = P( [tex]\frac{\bar X - \mu}{\frac{\sigma}{\sqrt{n} } }[/tex] [tex]\leq[/tex] [tex]\frac{34.5-35}{\frac{5.5}{\sqrt{25} } }[/tex] ) = P(Z [tex]\leq[/tex] -0.45) = 1 - P(Z [tex]\leq[/tex] 0.45)
= 1 - 0.6736 = 0.3264
Therefore, P(34.5 hrs < [tex]\bar X[/tex] < 36 hrs) = 0.8186 - 0.3264 = 0.4922.
AC is included between __________
Answer:
AC is included between <A and <C.
Step-by-step explanation:
i think, not sure tho
the height of a soccer ball that is kicked from the ground can be approximated by the function:
y = -12x^2 + 48x
where y is the height of the soccer ball in feet x seconds after it is kicked. What is the soccer ball's maximum height in feet?
Answer: 4 seconds
Step-by-step explanation:
x refers to time. Since we want to know how long it is in the air, we need to find the time (x) when the ball lands on the ground (y = 0)
0 = -12x² + 48x
0 = -12x(x - 4)
0 = -12x 0 = x - 4
0 = x 4 = x
x = 0 seconds is when the ball was kicked
x = 4 seconds is when the ball landed on the ground
Jan. 2 Purchased merchandise on account from Nunez Company, $20,000, terms 3/10, n/30. (Lily uses the perpetual inventory system.)
Feb. 1 Issued a 9%, 2-month, $20,000 note to Nunez in payment of account.
Mar. 31 Accrued interest for 2 months on Nunez note.
Apr. 1 Paid face value and interest on Nunez note.
July 1 Purchased equipment from Marson Equipment paying $10,000 in cash and signing a 10%, 3-month, $63,600 note.
Sept. 30 Accrued interest for 3 months on Marson note.
Oct. 1 Paid face value and interest on Marson note.
Dec. 1 Borrowed $22,800 from the Paola Bank by issuing a 3-month, 8% note with a face value of $22,800.
Dec. 31 Recognized interest expense for 1 month on Paola Bank note.
How many solutions does 2−9x=−6x+5−3x have?
Answer:
There are no values of x that make the equation true.
No solution
Step-by-step
hope it help
Hi
2-9x = -6x+5-3x
-9x+6x+3x = 5-2
0x = 3
as 0 ≠ 3 , there is no answer possible to your equation.
Two trains, X and Y, started simultaneously from opposite ends of a 100-mile route and traveled toward each other on parallel tracks. Train X, traveling at a constant rate, completed the 100-mile trip in 5 hours; Train Y, traveling at a constant rate, completed the 100-mile trip in 3 hours. How many miles had Train X traveled when it met Train Y?
(A) 37.5
(B) 40.0
(C) 60.0
(D) 62.5
(E) 77.5
Answer:
(A) 37.5 miles
Step-by-step explanation:
The trains x and y are travelling on tracks starting simultaneously from a from opposite ends of 100 miles roads.
Translate these information into a simple represention to visualize the problem. (Picture below)
■■■■■■■■■■■■■■■■■■■■■■■■■■
First let's calculate the velocity of both trains.
The velocity formula is:
● V = d/t
d is the distance travelled and t is the tile needed to do it.
● V(x) = 100/5 = 20 miles per hour
● V(y) = 100/3 = 33.33.. wich is approximatively 33 after rounding to the nearest unit.
■■■■■■■■■■■■■■■■■■■■■■■■■■
After calculateingboth velocities, Let's find when the trains meet.
First understand what does it mean matematically when both trains meet.
Go back to the representation and notice what happens when the trains meet.
Let t be that moment.
When x and y reches the meeting point at t, the sum of the distances they have travelled is equal to the total distance wich is 100 miles .
We khow that V = d/t so d = V×t
Let's find the expression of the distances both trains travelled when they have met each other.
● d = V(x) × t
● d' = V(y) × t
■■■■■■■■■■■■■■■■■■■■■■■■■■
So the equation will be:
● V(x) × t + V(y) × t = 100
Factor using t
● t (V(x) + V(y) ) = 100
Replace V(x) and V(y) by their values
● t (20+33) = 100
● 53 t = 100
Divide both sides by 53
● 53t /53 = 100/53
● t = 1.88
■■■■■■■■■■■■■■■■■■■■■■■■■
Replace t in the expression of the distance that train x has travelled when meeting y.
● d = V(x) × t
● d = 20 × 1.88
● d = 37.6 wich is approximatively 37.5 miles
i need help will rate you branliest
Answer:
d. The graph of g(x) is the graph of f(x) reflected over the x-axis.
Step-by-step explanation:
The standard transformation
g(x) = - f(x)
is a simple reflection about the x-axis.
So the answer is the last option.
Answer:
Last one
Step-by-step explanation:
The function we are interested in are g(x) and f(x).
● g(x)= (-1/x)
● f(x)= 1/x
Notice what happens when we input the same values in both functions.
● g(1) = -1/1 = -1
● f(x) = 1/1 = 1
●g(2) = -1/2 = -0.5
● f(2) = 1/2 = 0.5
Notice that we get opposite values by imputing the same number.
Wich means:
●f(x) = -g(x)
So the graph of g(x) is the graph of f(x) reflected over the x axis.
Find the slope of the line that passes through the points (1, -4) and (3,-1)
Hi there! :)
Answer:
[tex]\huge\boxed{m = \frac{3}{2}}[/tex]
Find the slope using the slope formula:
[tex]m = \frac{\text{rise}}{\text{run}} = \frac{y_2 - y_1}{x_2 - x_1}[/tex]
Plug in the coordinates of each point:
[tex]m = \frac{-1 - (-4)}{3 - 1}[/tex]
Simplify:
[tex]m = \frac{3}{2}[/tex]
Therefore, the slope of the line is 3/2.
Answer:
3/2
Step-by-step explanation:
The slope is given by
m = (y2-y1)/(x2-x1)
= ( -1 - -4)/(3-1)
= ( -1+4)/(2)
= ( 3/2)
A random sample of size results in a sample mean of and a sample standard deviation of . An independent sample of size results in a sample mean of and sample standard deviation of . Does this constitute sufficient evidence to conclude that the population means differ at the level of significance?
Answer:
A typical example would be when a statistician wishes to estimate the ... by the standard deviation ó) is known, then the standard error of the sample mean is given by the formula: ... The central limit theorem is a significant result which depends on sample size. ... So, the sample mean X/n has maximum variance 0.25/ n.
Step-by-step explanation:
A refrigeration system at your company uses temperature sensors fixed to read Celsius (0C) values, but the system operators in your control room understand only the Fahrenheit scale. You have been asked to make a Fahrenheit (°F) label for the high temperature alarm, which is set to ring whenever the system temperature rises above -10°C. What Fahrenheit value should you write on the label?
Answer:
14 °F
Step-by-step explanation:
To answer this problem, we will use the known celsius to fahrenheit conversion formula.
[Celsius * (9/5)] + 32 = Fahrenheit
Now we just plug in the value of celsius:
[-10 * (9/5)] + 32 = Fahrenheit
[ -2 * 9 ] + 32 = Fahrenheit
[ -18 ] + 32 = Fahrenheit
14 = Fahrenheit
So you should right 14(°F) on the label.
Cheers.
An octagonal pyramid ... how many faces does it have, how many vertices and how many edges? A triangular prism ... how many faces does it have, how many vertices and how many edges? a triangular pyramid ... how many faces does it have, how many vertices and how many edges?
1: 8 faces and 9 with the base 9 vertices and 16 edges
2: 3 faces and 5 with the bases 6 vertices and 9 edges
3: 3 faces and 4 with the base 4 vertices and 6 edges
Hope this can help you.
1: 8 faces and 9 with the base 9 vertices and 16 edges
2: 3 faces and 5 with the bases 6 vertices and 9 edges
3: 3 faces and 4 with the base 4 vertices and 6 edges
Help me please please please please
Answer:
1.
d. (-14) + (-8)
2.
a. (-14) + 8
Step-by-step explanation:
(-14) - 8 is equal to (-14) + (-8) because we still add two negative values so the result wouldn't change.
(-14) - (-8) is equal to (-14) + 8 because there's two negative sign in front of 8 and two negative values multiplied makes a positive result.
Answer:
1. D
2. A
Step-by-step explanation:
1. It asks you what expression has the same value as (-14)-8. All you need to do is find other equations that have the same value as that. So the equation is -14-8. IF a negative is outside a parenthesis with a positive number inside like -(+5), it is going to be -5. If it's both negative: -(-5), it will be +5. If it is both positive: +(+5), it is going to be +5.
IMPORTANT!
- and + = -
- and - = +
+ and + = +
What we are looking for: -14-8
So choice A is (-14)+8 which is simplified to -14+8. So, this one isn't right.
Choice B: 14-(-8)= 14+8. So, it's incorrect.
Choice C: 14+(-8)= 14-8. Again, it's not -14-8 so it's not right.
Choice D: (-14)+(-8)= -14-8. This equation matches the one we are looking for! So it's correct!
2. Same thing as number 1. Let's simplify the equation it wants us to find first.
(-14)-(-8)= -14+8
So -14+8 is what we are looking for.
Choice A: (-14)+8= -14+8. It matches! So it is correct. Let's look at the other options anyway.
Choice B: 14-(-8)= 14+8. Nope. Not right.
Choice C: 14+(-8)= 14-8 because - always beats +. So, this one is also incorrect.
Choice D: (-14)+(-8)= -14-8. Oops, this is also wrong. So choice A is the right answer.
Keep in mind, when you start getting questions like this with numbers inside the parenthesis as well, you want to remember the same rules for positive and negative, but also multiply the numbers together:
(When there is a number outside and inside a parentheses, multiply them.)
2(5)=10, CORRECT! 2+(5) is not 2 times 5. It's whatever is closest to the parentheses, in this case being the positive sign. So + and 5 is just 5!
IMPORTANT!
-2(-5)= - and - is positive, so positive (2 times 5). Positive 10.
-2(+5)= - and + is negative, so negative (2 times 5). Negative 10.
+2(+5)= + and + is positive, so positive (2 times 5). Positive 10.
The diameter of a large lawn ornament in the shape of a sphere is 16 inches. What is the approximate volume of the ornament? Use 3.14 for Pi. Round to the nearest tenth of a cubic inch. Recall the formula V = four-thirds pi r cubed.
Answer:
Sphere Volume = 4/3 * PI * radius^3
Sphere Volume = 4/3 * PI * 8^3
Sphere Volume = 4/3 * PI * 512
Sphere Volume = 2,144.7 cubic inches
Step-by-step explanation:
You know only the given information about
the measures of the angles of a triangle. Find the probability that the triangle is equiangular.
39. Each is a multiple of 12.
Since they are multiples if 12
The possibilities are
12, 12, 156
12,24,144
12,36,132
12,48,120
12,60,108
12,72,96
12,84,84
24,24,132
24,36,120
24,48,108
24,60,96
24,72,84
36,36,108
36,48,96
36,60,84
36,72,72
48,48,84
48,60,72
60,60,60
Hence the probability is 1/19 or 0.0526
A plot of land has vertices as follows, where each coordinate is a measurement in feet. Find the perimeter of the plot of land. (1,7),(7,7),(7,1),(1,1) please help and explain how to do this type of thing because i am lost
Answer:
Perimeter of ABCD = 36 ft
Step-by-step explanation:
Given:
A (1,7)
B (7,7)
C (7,1)
D (1,1)
Find:
Perimeter of ABCD
Computation:
Distance between two point = √(x1-x2)² + (y1-y2)²
So,
AB = √(1-7)²+(7-7)²
AB = 6 ft
BC = √(7-7)²+(7-1)²
BC = 6 ft
CD = √(7-1)²+(1-1)²
CD = 6 ft
DA = √(1-1)²+(1-7)²
DA = 6 ft
Perimeter of ABCD = AB + BC + CD + DA
Perimeter of ABCD = 6 + 6 + 6 +6
Perimeter of ABCD = 36 ft
The perimeter of the plot is the sum of side length of the plot of land.
The perimeter of the plot is 24 feet.
Represent the vertices as follows:
[tex]W = (1,7)[/tex]
[tex]X = (7,7)[/tex]
[tex]Y = (7,1)[/tex]
[tex]Z = (1,1)[/tex]
First, we calculate the side length using the following distance formula:
[tex]d = \sqrt{(x_1 - x_2)^2 + (y_1 - y_2)^2}[/tex]
So, we have:
[tex]WX = \sqrt{(1- 7)^2 + (7- 7)^2} = \sqrt{36} = 6[/tex]
[tex]XY = \sqrt{(7- 7)^2 + (7- 1)^2} = \sqrt{36} = 6[/tex]
[tex]YZ = \sqrt{(7- 1)^2 + (1- 1)^2} = \sqrt{36} = 6[/tex]
[tex]ZW = \sqrt{(1- 1)^2 + (1- 7)^2} = \sqrt{36} = 6[/tex]
The perimeter (P) is then calculated as follows:
[tex]P = WX + XY + YZ + ZW[/tex]
So, we have:
[tex]P = 6 + 6 + 6 + 6[/tex]
[tex]P = 24[/tex]
Hence, the perimeter of the plot of land is 24 feet.
Read more about perimeters at:
https://brainly.com/question/394193
Solve for x: −3|2x + 6| = −12.
Answer:
x = -1 or x = -5
Step-by-step explanation:
−3 * |2x + 6| = −12 / -3
|2x + 6| = 4
because this is an absolute value equation there are 2 solutions:
2x + 6 = 4 or 2x + 6 = -4
2x = -2 or 2x = -10
x = -1 or x = -5
Answer:
x = -1 or x = -5
Step-by-step explanation:
cuz it is
Adrianna has a court to play basketball with her friends.
The it is 600 square feet. It is 30 feet long. How many feet across is
court?
Answer:
Hey there!
The area of a rectangle is the length times width.
Thus, we can write the equation, 600=30w.
Solving for the width, we get that the width is equal to 20 ft.
Let me know if this helps :)
Answer:
20 feet across.
Step-by-step explanation:
You will have to do a simple equation solve.
x is how many feet across the court is.
* could be our multiplying sign
600 = 30*x
Now divide 30 on both sides. 30 will cross out (since 30/30 is 1 and anything times 1 is the same number as it was before) on the right side and 600/30 is 20 so we change the 600 to 20.
That leaves 20 = x.
So it is 20 feet across.
Jamal has two investments, one in Company A, and another in Company B. Jamal purchased 300 shares in Company A at $1.45 per share. Since purchasing the shares, the price per share increased to $1.65 per share, after which Jamal decided to sell, realizing a profit. At the same time, Jamal purchased 200 shares in Company B at $1.20 per share. Since purchasing the shares, the share price fell to $1.10 per share, after which Jamal decided to sell the shares, suffering a loss. Calculate the total profit that Jamal received from his two investments.
Answer:
$20
Step-by-step explanation:
Company A:
Buy 300 shares at $1.45 per share.
Sell 300 shares at $1.65 per share.
Profit: ($1.65 - $1.45) * 300 = $60
Company B:
Buy 200 shares at $1.20 per share.
Sell 200 shares at $1.10 per share.
Loss: ($1.20 - $1.10) * 200 = $20
Net profit:
$40 - $20 = $20
Answer:
Step-by-step explanation:
Profit on Company A =$(1.65−1.45)×300=$60.
Loss on Company B =$(1.20−1.10)×200=$20.
Therefore the total profit Jamal achieved was $60−$20=$40.
When is it easier to use the addition method rather than the substitution method to solve a system of equations?
Answer: When the addition of two or more equations leads to the elimination of one of the variables.
Step-by-step explanation:
When we have a system of equations, the addition method seems to be useful only when adding the equations will lead to the elimination of one of the variables:
An example of this can be, for the variables x and y:
3*x + x*y - 2*y = 3
x^2 + x*y - 2y = 42
now we can "add" (actually subtract) the equations and get (eq2 minus eq1)
(x^2 + x*y - 2y) - (3*x + x*y - 2*y ) = 42 - 3
x^2 - 3*x = 39
x^2 - 3*x - 39 = 0
And now we can solve it for x, and then find the value of y.
PLEASE ANSWER ASAP!!!
Equation in the picture
Solve for r in the equation in the picture. You must use the LCD (Least Common Denominator) to simplify. You can also use cross products to solve.
Must show work
A. r = 19
B. r = 21
C. r = 25
D. r = 30
any unrelated answer will be reported
Answer:
r = 19
Step-by-step explanation:
( r-5) /2 = ( r+2) /3
The least common denominator is 6
3/3 *( r-5) /2 = ( r+2) /3 * 2/2
3( r-5) /6 = 2( r+2) /6
Since the denominators are the same, the numerators are the same
3( r-5) = 2(r+2)
Distribute
3r -15 = 2r+4
Subtract 2r from each side
3r-2r -15 = 2r+4-2r
r-15 =4
Add 15 to each side
r-15+15 = 4+15
r = 19
1. Solve the system of equations. y = –3x + 4 x + 4y = –6 A. x = –2,y = –1 B. x = –2,y = 10 C. x = 2,y = –2 D. x = 3,y = –5 E. x = 4,y = –8
Answer:
C. x = 2, y = -2
Step-by-step explanation:
y = -3x + 4
x + 4y = -6
x + 4(-3x + 4) = -6
x - 12x + 16 = -6
-11x = -22
x = 2
y = -3(2) + 4 = -2
Find the equation of a parabola that has a vertex (3,5) and passes through the point (1,13).
Oy= -27 - 3)' +5
Oy=2(x + 3) - 5
Oy=2(0 - 3)' + 5
Oy= -3(2 – 3) + 5
PLEASE HELP ME!!
Answer:
y = 2(x - 3)² + 5
Step-by-step explanation:
The equation of a parabola in vertex form is
y = a(x - h)² + k
where (h, k) are the coordinates of the vertex and a is a multiplier
Here (h, k) = (3, 5), thus
y = a(x - 3)² + 5
To find a substitute (1, 13) into the equation
13 = a(1 - 3)² + 5 ( subtract 5 from both sides )
8 = 4a ( divide both sides by 4 )
a = 2, then
y = 2(x - 3)² + 5 ← equation of parabola in vertex form
if the LCM and the HCF of two numbers are 9 and 3, respectively, what are the numbers?
Hey There!
Answer:
HCF = 9 (With the two numbers) - 18,9LCM = 3 (with the two numbers) - 6,9Step-by-step explanation:
HCF
If HCF is ''9'' that means that ''9'' is the divisible of two numbers.
So 18 and 19 can be divided by 9 and that's the highest divisible for both factors.
And always remeber the answer is a ''Prime factor.''
LCM
If LCM is ''3'' that means ''3'' is the lowest common multiple out of two numbers.
Hope this helps!
Have a nice Day!:)
Find the value of x.
Answer:
5
Step-by-step explanation:
This shape is formed by two right triangles.
Let's start by the little one.
Let y be the third side.
Using the Pythagorian theorem we get:
y^2 = 6^2 + 3^2
y^2 = 36 + 9
y^2 = 45
y = 3√(5)
●●●●●●●●●●●●●●●●●●●●●●●●
Now let's focus on the second triangle. Let z be the third side.
The Pythagorian theorem:
6^2 + x^2 = z^2
Using the Pythagorian theorem on the big triangle :
[3√(5)]^2 + z^2 = (3+x)^2
45 + z^2 = 3x^2 + 6x + 9
36 +z^2 = 3x^2 +6x
So we have a system of equations.
36+ x^2 = z^2
36 +z^2 = 3x^2 +6x
We want to khow the value of x so we will eliminate z .
Add (36+x^2 -z^2 =0) to the second one.
36 + x^2-z^2+36+z^2 = 3x^2+6x
72 + x^2 = 3x^2 +6x
72 - 2x^2 -6x = 0
Multipy it by -1 to reduce the number of - signs
2x^2 + 6x -72 = 0
This is a quadratic equation
Let A be the discriminant
● a = 2
● b = 6
● c = -72
A = b^2-4ac
A = 36 -4*2*(-72) = 36 + 8*72 =612
So this equation has two solutions
The root square of 612 is approximatively 25.
● (-6-25)/4 = -31/4 = -7.75
● (-6+25)/4 = 19/4 = 4.75 wich is approximatively 5
A distance cannot be negative so x = 5
A charity organization is holding a food drive with a goal to collect at least 1,000 cans of
food by the end of the month. It currently has 565 cans from donations and is having an
event where 87 guests will attend and bring cans. Which solution set represents the
number of cans each guest must bring to meet the goal?
+
OA
++
0
1
2
3
4
5
6
7
8
9
10
---
+
OB. 4
+
0
1
2
3
4
5
6
7
8
9
10
OC.
+
1
2
3
5
6
7
8
9
10
OD. +
+
++
-
6
+
7.
+
0
1
2
3
4
5
8
9
10
Answer:
Each guest must bring 5 cans.
Step-by-step explanation:
1000-565=435
435/87=5
y varies directly as the square of R. If y is 7 when R is 3, find y when R is 15 . a) Write the variation. b) Find y when R is 15.
Step-by-step explanation:
a.
[tex]y = k {r}^{2} [/tex]
[tex]7 = k {3}^{2} [/tex]
[tex]7 = 9k[/tex]
[tex]k \: = \frac{7}{9} [/tex]
[tex]y \: = \frac{7}{9} {r}^{2} [/tex]
b.
[tex]y \: = \frac{7}{9} \times {15}^{2} [/tex]
[tex]y = \frac{7}{9} \times 225[/tex]
y = 175
two identical rubber balls are dropped from different heights. Ball 1 is dropped from a height of 109 feet, and ball 2 is dropped from a height of 260 feet. Use the function f(t) -16t^2+h to determine the current height, f(t), of a ball from a height h, over given time t.
When does ball 1 reach the ground? Round to the nearest hundredth
Answer: 5.22 seconds
Step-by-step explanation:
t represents time and y represents the height.
Since we want to know when the ball hits the ground, find t when y = 0
Ball 1 starts at a height of 109 --> h = 109
0 = -16t² + 109
16t² = 109
[tex]t^2=\dfrac{109}{16}\\[/tex]
[tex]t=\sqrt{\dfrac{109}{16}}[/tex]
[tex]t=\dfrac{\sqrt{109}}{2}[/tex]
t = 5.22
=> H = 109
=> 0 = -16t² + 109
=> 16t² = 109
=> t² = 109/16
=> t = 109/2
=> t = 5.22 sec
Therefore, 5.22 second is the answer.
Find the value of angle X. x = 40 x = 55 x = 109 x = 130 I will mark as Brainliest
Answer:
130 degree
Step-by-step explanation:
Interior angles of the triangle:
81, 49, (180-x)
and by sum of all angles of triangle is 180 degree,
therefore,
81 + 49 + 180 - x = 180
x = 130 degree
Alex wants to sew a pillow in the shape below. How many square yards of fabric are needed to sew the pillow? Fabric is only sold in increments of ¼ yard.
The shape is missing, so i have attached it.
Answer:
2.6
Step-by-step explanation:
From the image attached, the diameter of the inner semi - circle is 0.5 yards while the length of each side of the pillow is 0.2 yards.
Thus, for us to find the length of the seam which is along the edges of the pillow, we will calculate the perimeter of the outer semicircle, then add the perimeter of the inner semicircle and also add the sides too.
Now, due to the fact that the length of the sides of the pillow are 0.2 yards each, the diameter of the outer circle would be;
0.5 + 0.2 + 0.2 = 0.9 yards. So, the perimeter of the outer semicircle is,
P0 = πd/2 = π × 0.9/2 =0.45π yds
The perimeter of the inner semicircle would be given as;
PI = πd/2 = π × 0.5/2 =0.25π yds.
Thus, we can calculate the total perimeter of the pillow as;
PT = P0 + PI + 0.2 + 0.2
PT = 0.45π + 0.25π + 0.2 + 0.2
PT ≈ 2.6 yards
Alex will need 2.6 yds
Answer:
0.5
Step-by-step explanation:
What is the image of point (8,-4) under the rotation R90° about the origin?
A) (8,4)
B) (4,8)
C) (-4,8)
D) (-4,-8)
Answer:
D). (-4,-8)
Step-by-step explanation:
An image at (8,-4) if rotated at an angle of 90° wipl have another location.
First of all, an image at (8,-4) is in the fourth quadrant, and if it's to rotate clockwise at 90° iths supposed to be in the third quadrant.
And in the third quadrant both x and y is negative.
So the new position is at (-4,-8)
The manager of a garden shop mixes grass seed that is 60% rye grass with 140 pound of grass seed that is 80% rye grass to make a mixture that is 74% rye grass. How much of the 60% mixture is used?
Answer:
60 pounds
Step-by-step explanation:
Let x = number of pounds of grass seeds A
The number of pounds of grass seed B = 140 pounds
Total pounds of the resulting mixture = (140 + x) pounds
Rye grass A = 60% = 0.6
Rye grass B = 80% = 0.8
Total percent of mixture formed = 74% = 0.74
Hence, we have the equation:
0.6x + 0.8 × 140 = 0.74 ( 140 + x)
0.6x + 112 = 103.6 + 0.74x
Collect like terms
112 - 103.6 = 0.74x - 0.6x
8.4 = 0.14x
x = 60 pounds
Therefore, the quantity of the 60% mixture used is 60 pounds.
The manager of a garden shop mixes grass seed that is 60% rye grass with 140 pound of grass seed that is 80% rye grass to make a mixture that is 74% rye grass. How much of the 60% mixture is used?
