Solve the system of equations for the variables: x+2y-z=3 x+y-2z= -1
Answers
Answer:
z=0
x= -5
y=4
Step-by-step explanation:
Check the attachment please
Hope this helps :)
Step-by-step explanation:
x + 2y − z = 3
x + y − 2z = -1
There are three variables but only two equations, so this system of equations is undefined. We cannot solve for the variables, but we can eliminate one of them and reduce this to a single equation.
Double the first equation:
2x + 4y − 2z = 6
Subtract the second equation.
(2x + 4y − 2z) − (x + y − 2z) = (6) − (-1)
2x + 4y − 2z − x − y + 2z = 7
x + 3y = 7
Related Questions
In 1998, as an advertising campaign, the Nabisco Company announced a "1000 Chips Challenge," claiming that every 18-ounce bag of their Chips Ahoy cookies contained at least 1000 chocolate chips. Dedicated statistics students at the Air Force Academy (no kidding) purchased some randomly selected bags of cookies and counted the chocolate chips. Some of their data are given below. 1219 1214 1087 1200 1419 1121 1325 1345 1244 1258 1356 1132 1191 1270 1295 1135 Find a 95% confidence interval for the mean number of chips in a bag of Chips Ahoy Cookies.
Answers
Answer:
A 95% confidence interval for the mean number of chips in a bag of Chips Ahoy Cookies is [1187.96, 1288.44].
Step-by-step explanation:
We are given that statistics students at the Air Force Academy (no kidding) purchased some randomly selected bags of cookies and counted the chocolate chips.
Some of their data are given below; 1219, 1214, 1087, 1200, 1419, 1121, 1325, 1345, 1244, 1258, 1356, 1132, 1191, 1270, 1295, 1135.
Firstly, the pivotal quantity for finding the confidence interval for the population mean is given by;
P.Q. = [tex]\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }[/tex] ~ [tex]t_n_-_1[/tex]
where, [tex]\bar X[/tex] = sample mean number of chocolate chips = [tex]\frac{\sum X}{n}[/tex] = 1238.2
s = sample standard deviation = [tex]\sqrt{\frac{\sum (X-\bar X)^{2} }{n-1} }[/tex] = 94.3
n = sample of car drivers = 16
[tex]\mu[/tex] = population mean number of chips in a bag
Here for constructing a 95% confidence interval we have used a One-sample t-test statistics because we don't know about population standard deviation.
So, 95% confidence interval for the population mean, [tex]\mu[/tex] is ;
P(-2.131 < [tex]t_1_5[/tex] < 2.131) = 0.95 {As the critical value of t at 15 degrees of
freedom are -2.131 & 2.131 with P = 2.5%}
P(-2.131 < [tex]\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }[/tex] < 2.131) = 0.95
P( [tex]-2.131 \times {\frac{s}{\sqrt{n} } }[/tex] < [tex]{\bar X-\mu}[/tex] < [tex]2.131 \times {\frac{s}{\sqrt{n} } }[/tex] ) = 0.95
P( [tex]\bar X-2.131 \times {\frac{s}{\sqrt{n} } }[/tex] < [tex]\mu[/tex] < [tex]\bar X+2.131 \times {\frac{s}{\sqrt{n} } }[/tex] ) = 0.95
95% confidence interval for [tex]\mu[/tex] = [ [tex]\bar X-2.131 \times {\frac{s}{\sqrt{n} } }[/tex] , [tex]\bar X+2.131 \times {\frac{s}{\sqrt{n} } }[/tex] ]
= [ [tex]1238.2-2.131 \times {\frac{94.3}{\sqrt{16} } }[/tex] , [tex]1238.2+2.131 \times {\frac{94.3}{\sqrt{16} } }[/tex] ]
= [1187.96, 1288.44]
Therefore, a 95% confidence interval for the mean number of chips in a bag of Chips Ahoy Cookies is [1187.96, 1288.44].
Find the solution of the given initial value problem. ty' + 2y = sin t, y π 2 = 9, t > 0 y(t) =
Answers
For the ODE
[tex]ty'+2y=\sin t[/tex]
multiply both sides by t so that the left side can be condensed into the derivative of a product:
[tex]t^2y'+2ty=t\sin t[/tex]
[tex]\implies(t^2y)'=t\sin t[/tex]
Integrate both sides with respect to t :
[tex]t^2y=\displaystyle\int t\sin t\,\mathrm dt=\sin t-t\cos t+C[/tex]
Divide both sides by [tex]t^2[/tex] to solve for y :
[tex]y(t)=\dfrac{\sin t}{t^2}-\dfrac{\cos t}t+\dfrac C{t^2}[/tex]
Now use the initial condition to solve for C :
[tex]y\left(\dfrac\pi2\right)=9\implies9=\dfrac{\sin\frac\pi2}{\frac{\pi^2}4}-\dfrac{\cos\frac\pi2}{\frac\pi2}+\dfrac C{\frac{\pi^2}4}[/tex]
[tex]\implies9=\dfrac4{\pi^2}(1+C)[/tex]
[tex]\implies C=\dfrac{9\pi^2}4-1[/tex]
So the particular solution to the IVP is
[tex]y(t)=\dfrac{\sin t}{t^2}-\dfrac{\cos t}t+\dfrac{\frac{9\pi^2}4-1}{t^2}[/tex]
or
[tex]y(t)=\dfrac{4\sin t-4t\cos t+9\pi^2-4}{4t^2}[/tex]
Dairy cows at large commercial farms often receive injections of bST (Bovine Somatotropin), a hormone used to spur milk production. Bauman et al. (Journal of Dairy Science, 1989) reported that 12 cows given bST produced an average of 28.0 kg/d of milk. Assume that the standart deviation of milk production is 2.25 kg/d.
Requried:
a. Find a 99% confidence interval for the true mean milk production.
b. If the farms want the confidence interval to be no wider than ± 1.25 kg/d, what level of confidence would they need to use?
Answers
Answer:
a) 26.33 kg/d and 29.67 kg/d
b) 94.5%
Step-by-step explanation:
a. Find a 99% confidence interval for the true mean milk production.
We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:
[tex]\alpha = \frac{1-0.99}{2} = 0.005[/tex]
Now, we have to find z in the Ztable as such z has a pvalue of [tex]1-\alpha[/tex].
So it is z with a pvalue of [tex]1-0.005 = 0.995[/tex], so [tex]z = 2.575[/tex]
Now, find the margin of error M as such
[tex]M = z*\frac{\sigma}{\sqrt{n}}[/tex]
In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.
[tex]M = 2.575*\frac{2.25}{\sqrt{12}} = 1.67[/tex]
The lower end of the interval is the sample mean subtracted by M. So it is 28 - 1.67 = 26.33 kg/d
The upper end of the interval is the sample mean added to M. So it is 28 + 1.67 = 29.67 kg/d
The 99% confidence interval for the true mean milk production is between 26.33 kg/d and 29.67 kg/d
b. If the farms want the confidence interval to be no wider than ± 1.25 kg/d, what level of confidence would they need to use?
We need to find z initially, when M = 1.25.
[tex]M = z*\frac{2.25}{\sqrt{12}} = 1.67[/tex]
[tex]1.25 = z*\frac{2.25}{\sqrt{12}} = 1.67[/tex]
[tex]2.25z = 1.25\sqrt{12}[/tex]
[tex]z = \frac{1.25\sqrt{12}}{2.25}[/tex]
[tex]z = 1.92[/tex]
When [tex]z = 1.92[/tex], it has a pvalue of 0.9725.
1 - 2*(1 - 0.9725) = 0.945
So we should use a confidence level of 94.5%.
Round 2826 to the nearest hundred.
Answers
Answer:
2800
Step-by-step explanation:
2826 to the nearest hundred is 2800
Which expression is equivalent to 3m + 1 - m? 2 + m - 1 + m 1 + m 3m - 1 3m
Answers
Answer:
2m + 1
Step-by-step explanation:
Simply combine like terms. m terms go with m terms and constants go with constants.
Answer:
2m + 1
Step-by-step explanation:
3m + 1 - m =
= 3m - m + 1
= 2m + 1
what is u over 4-4= -20
Answers
u/4 - 4 = -20
Add 4 to both sides:
u/4 = -16
Multiply both sides by 4:
u = -64
Answer:
u=-64
Step-by-step explanation:
u/4 -4 = -20
First add 4 to both sides.
u/4=-16
Now multiply both sides by 4
u=-64
Given X= 5+ V16 select the value(s) of x. Check
all of the boxes that apply.
-11
1
9
21
Answers
Answer:
[tex]x = 9\ or\ x = 1[/tex]
Step-by-step explanation:
Given
[tex]x = 5 + \sqrt{16}[/tex]
Required
Find the value of x
[tex]x = 5 + \sqrt{16}[/tex]
We start by taking the square root of 16; Square root of 16 is +4 or -4; So, we have:-
[tex]x = 5 \±4[/tex]
The expression above can be split into two; This is as follows
[tex]x = 5 + 4\ or\ x = 5 - 4[/tex]
[tex]x = 9\ or\ x = 1[/tex]
Hence, the solution to [tex]x = 5 + \sqrt{16}[/tex] is B. 1 and C. 9
Answer:
its b and c
Step-by-step explanation:
the guy who answered first said so
also i just did it
The volume of a rectangular prism is given by the formula V = lwh, where l is the length of the prism, w is the width, and h is the height. Suppose a box in the shape of a rectangular prism has length (2a + 11), width (5a – 12), and height (a + 6). Which expression represents the volume of the box?
Answers
Answer:
Volume = 10a³ + 91a² + 54a - 792
Step-by-step explanation:
In the absence of answer choices, let's find the expression for the volume.
Given: Volume = length×width×height
V = lwh
length =(2a + 11)
width =(5a – 12)
height= (a + 6)
V = (2a + 11)(5a – 12) (a + 6)
Expand the first two brackets using distributive property
V = (10a² -24a +55a - 132)(a + 6)
Collect like terms
V = (10a² + 31a -132)(a + 6)
Expand the two brackets using distributive property
V = 10a³ + 31a² - 132a + 60a² + 186a - 792
Collect like terms
V = 10a³ + 91a² + 54a - 792
The expression that represents the volume of the box = 10a³ + 91a² + 54a - 792
Answer:
Volume = 10a³ + 91a² + 54a - 792
Step-by-step explanation:
evaluate 25.1 * 2.51 in two decimal places
Answers
Answer:
63.00
Step-by-step explanation:
25.1 × 2.51
Multiply.
= 63.001
Round to two decimal places.
63.00
Answer:
63.00
Step-by-step explanation:
when u multiply 25.1 by 25.1 you get 630.01. Then u have to move the decimal over to the left once and then u get 63.00
What is the justification for step 2 in the solution process?
Answers
Answer:
Answer C
Step-by-step explanation:
You are balancing this equation out by subtracting 7x from both sides. This means you are using the subtraction property of equality.
2) Find the diameter.
4) If the diameter is equal to 3 inches ,d=
Answers
Answer:
d = 3 in
Step-by-step explanation:
Since we are trying to find the diameter, and the diameter is given to us as 3 in, our diameter is 3 in.
how large of a sample of state employee should be taken if we want to estimate with 98% confidence the mean salary to within 2000 g
Answers
The question is incomplete! Complete question along with answer and step by step explanation is provided below.
Question:
How large of a sample of state employees should be taken if we want to estimate with 98% confidence the mean salary to be within $2,000? The population standard deviation is assumed to be $10,500. z-value for 98% confidence level is 2.326.
Answer:
Sample size = n = 150
Step-by-step explanation:
Recall that the margin of error is given by
[tex]$ MoE = z \cdot (\frac{\sigma}{\sqrt{n} } ) $\\\\[/tex]
Re-arranging for the sample size (n)
[tex]$ n = (\frac{z \cdot \sigma }{MoE})^{2} $[/tex]
Where z is the value of z-score corresponding to the 98% confidence level.
Since we want mean salary to be within $2,000, therefore, the margin of error is 2,000.
The z-score for a 98% confidence level is 2.326
So the required sample size is
[tex]n = (\frac{2.326 \cdot 10,500 }{2,000})^{2}\\\\n = (12.212)^{2}\\\\n = 149.13\\\\n = 150[/tex]
Therefore, we need to take a sample size of at least 150 state employees to estimate with 98% confidence the mean salary to be within $2,000.
Select the correct interpretation of the probability of getting an 11 when a pair of dice is rolled. Interpret an event as significant if its probability is less than or equal to 0.05. Select one: a. Significant at .055 b. Not significant at .945 c. Not significant at .055 d. Significant at .028
Answers
Answer:
c. Not significant at .055
Step-by-step explanation:
When a pair of dice is rolled, we have 6²=36 possible outcomes. Only 2 of these outcomes have a total score of 11:
When the first dice is 5 and the second is 6.When the first dice is 6 and the second is 5.Then, we can calculate the probability of getting 11 as the quotient between the successs outcomes and the total outcomes.
Then, the probability of getting 11 is:
[tex]P=\dfrac{X}{N}=\dfrac{2}{36}=0.055[/tex]
This probability is not equal or less than 0.05, so it is not significant at 0.055.
Suppose Gabe, an elementary school student, has just finished dinner with his mother, Judy. Eyeing the nearby cookie jar, Gabe asks his mother if he can have a cookie for dessert. She tells Gabe that she needs to check his backpack to make sure k. Gabe cannot remember where he left his backpack, but he knows for sure that he did not complete his bomework and will not be alowed to cat a cookie. Gabe believes his only option is to quickly steal a cookie while his mother is out of the room. Judy then leanves the room to look for Gabe's backpack. Assome that Judy could return at any time in the next 90 seconds with equal probability, For the first 40 seconds, Gabe sheepishly wonders if he will get caught rying to grab a nearby cookie. After waiting and not secing his mother, Gabe decides that he needs a cookie and begins to take one from the jar Assuming it takes Gabe 30 seconds to grab a cookie from the jar and devour it without a trace, what is the probability that his mother returns in time to catch Gabe stealing a cookie?
Answers
Answer:
0.56
Step-by-step explanation:
What is the probability that his mother returns just in time to catch Gabe stealing a cookie?
The probability of this is the same as 1 minus the probability that Gabe is NOT caught.
- Judy could return at anytime in the next 90 seconds
- Gabe spends the first 40 seconds pondering... time wasted=40secs
- It takes 30 seconds (out of the remaining 50secs) to finish eating a cookie without a trace
- The question says that Gabe was going to do it, so he probably did
Now we're looking for the probability that he gets caught. That is, probability that he does not "successfully" complete the 30secs task within the remaining 50secs.
Remember that each second has an equal probability of being the second that Judy comes back in. The latter of the 90 seconds does not carry a higher probability!
So the probability of catching Gabe (despite the 30secs it takes to complete his task) is 50/90 which is equal to 0.56
I’m Confused On The Question
Answers
factorise 12x² + x - 20
Answers
━━━━━━━☆☆━━━━━━━
▹ Answer
(3x + 4) * (4x - 5)
▹ Step-by-Step Explanation
12x² + x - 20
Rewrite
12x² + 16x - 15x - 20
Factor out
4x(3x + 4) - 15x - 20
4x(3x + 4) - 5(3x + 4)
Factor
(3x + 4) * (4x - 5)
Hope this helps!
- CloutAnswers ❁
Brainliest is greatly appreciated!
━━━━━━━☆☆━━━━━━━
Write a pair of integers whose sum is- -8
Answers
Answer:
-3+(-5)
Checking our answer:
Adding this does indeed give -8
4. A rectangle-shaped picture frame has a length of 4b cm and an area of 12ab² square cm. Find the width. *
Answers
Answer:
3ab
Step-by-step explanation:
area = length * width
width = area/length
width = (12ab^2)/(4b)
width = 3ab
Use the counting principle to determine the number of elements in the sample space. Two digits are selected without replacement from the digits 1, 2, 3, and 4.
Answers
Answer:
if the order of the digit matters, we have:
options: 1, 2, 3, 4.
We want to select two digits.
First selection: we have 4 options
Second selection: we have 3 options (because we already selected one in the first selection)
The total number of elements in the sample space, or the total number of combinations, is equal to the product of the number of options in each selection, this is:
P = 4*3 = 12
Which of the following is not a congruence theorem or postulate? A. SSS B. SAS C. SSA D. AAS
Answers
Answer:
SSA the only other right one missing is ASA
Hope that helps
Factor completely 5x(x + 3) + 6(x + 3). (1 point)
Answers
Answer:
The answer is ( 5x + 6 ) ( x + 3 )Step-by-step explanation:
5x(x + 3) + 6(x + 3)
The final answer is
( 5x + 6 ) ( x + 3 )
Hope this helps you
What number is 408% of 568?
Answers
Answer:
2317.44
Step-by-step explanation:
Solution for What is 408 percent of 568:
408 percent *568 =
(408:100)*568 =
(408*568):100 =
231744:100 = 2317.44
Answer:
2317.44
Step-by-step explanation:
In order to determine the average price of hotel rooms in Atlanta, a sample of 64 hotels was selected. It was determined that the average price of the rooms in the sample was $112. The population standard deviation is known to be $16.
a. Which form of the hypotheses should be used to test whether or not the average room price is significantly different from $108.50?
H0:
-mu is greater than or equal to $108.50
mu is greater than $108.50
mu is less than $108.50mu is less than or equal to $108.50
mu is equal to $108.50mu is not equal to $108.50
Ha: -
-mu is greater than or equal to $108.50
mu is greater than $108.50mu is less than $108.50
mu is less than or equal to $108.50
mu is equal to $108.50mu is not equal to $108.50
b. Test to determine if whether or not the average room price is significantly different from $108.50, using an alpha level of .05.
Reject H0
or
Fail to reject H0
Answers
Answer:
Step-by-step explanation:
H0: mu is equal to $108.50
Ha: mu is not equal to $108.50
This test is a two tailed test and using the z tat formula, we can ascertain if there is a difference.
z = x-u / sd/√n
Where x is $112, u is $108.50 sd is $16 and n is 64
z = 112-108.50 / 16/√64
z = 3.5/(16/8)
z = 3.5/2
z = 1.75
To help us arrive at a conclusion, we need to find the p value using alpha id = 0.05. The p value is 0.08. Since the p value is great than 0.05, we fail to reject the null and conclude that there is not enough statistical evidence to prove that the average room price is significantly different from $108.50
find the value of x that makes abcd a parallelogram
Answers
The 4 angles need to add to 360.
2 of them are 70
The other two need to equal 360-140 = 220
They are both the same so one angle needs to equal 220/2 = 110
Now find x:
X + 60 = 110
Subtract 60 from both sides:
X = 50. The answer is D
Simply the expression 3.4-1/2(0.75)
Answers
Answer:
3.025
Step-by-step explanation:
3.4-1/2(0.75)
3.4-0.375
3.025
Find the area of the yellow region.
Round to the nearest tenth.
15 cm
15 cm
Area = [ ? ] cm2
Answers
Answer:
48.3 cm²
Step-by-step explanation:
Let A be the area of the yellow region
A= the area of the square - the area of the quarter square
A= 15²-(15²*π)/4= 48.28≈ 48.3 cm²
What is the value of X in equation? 1/3 X - 2/3 = - 18
Answers
Answer:
x=-52
Step-by-step explanation:
1/3x=-17 1/3
x=-52
There are 60 people at the subway station 12 of them jumped the
turnstile. What percentage of people jumped the turnstile? What
percentage of people paid?
Answers
Answer:
20% jumped the turnstile
80% paid
Step-by-step explanation:
We can calculate the percent of people that jumped it by dividing the number that did by the total:
12/60 = 0.2, which is 20%
If 20% jumped it, then this means 80% paid.
Answer:
jumped= 20%
paid= 80%
Step-by-step explanation:
[tex]\frac{12}{60}[/tex]×100 = 20%
[tex]\frac{48}{60}[/tex]×100 = 80%
find the value of x. m<2= x + 119
Answers
Answer: x = -10
Step-by-step explanation:
see image
A) congruent sides implies congruent angles A = 64°
B) Use the Triangle Sum Theorem: 64° + 64° + B = 180° --> B = 52°
C) B and C are complimentary angles: 52° + C = 90° --> C = 38°
D) Use the Triangle Sum Theorem knowing that congruent sides implies congruent angles: 38° + 2D = 180° --> D = 71°
∠2) D and ∠2 are supplementary angles: 71° + ∠2 = 180° --> ∠2 = 109°
Solve for x:
109° = x + 119
-10 = x
Answer:
x = -10
Step-by-step explanation:
Find the measure of angle m∠2
The triangles are isosceles triangles, the base angles are equal.
The other base angle is also 64°.
Using Triangle Sum Theorem.
64 + 64 + y = 180
y = 52
The top angle is 52°.
The whole angle is 90°.
90 - 52 = 38
The second triangle has base angles equal.
Using Triangle Sum Theorem.
38 + z + z = 180
z = 71
The two base angles are 71°.
Angles on a straight line add up to 180°.
71 + m∠2 = 180
m∠2 = 109
The measure of m∠2 is 109°
Find the value of x
m∠2 = x + 119
109 = x + 119
x = 109 - 119
x = -10
An article gave the accompanying data on ultimate load (kN) for two different types of beams. Assuming the underlying distributions are Normal, calculate and interpret a 99% Cl for the difference between the true average load for the fiberglass beams and that for the carbon beams.
Type Sample size Sample Mean Sample SD
Fiberglass grid 26 33.4 2.2
Commercial carbon 26 42.8 4.3
grid
1. Calculate and interpret a 99% Cl for true average stance duration among elderly individuals.
2. Carry out a test of hypotheses at significance level 0.05 to decide whether true average stance duration is larger among elderly individuals than younger individuals.
Answers
Answer:
The 99% confidence interval for the difference between the true average load for the fiberglass beams and that for the carbon beams is (-11.937, -6.863).
Step-by-step explanation:
We have to calculate a 99% confidence interval for the difference between the true average load for the fiberglass beams and that for the carbon beams.
The sample 1 (Fiberglass), of size n1=26 has a mean of 33.4 and a standard deviation of 2.2.
The sample 2 (Carbon), of size n2=26 has a mean of 42.8 and a standard deviation of 4.3.
The difference between sample means is Md=-9.4.
[tex]M_d=M_1-M_2=33.4-42.8=-9.4[/tex]
The estimated standard error of the difference between means is computed using the formula:
[tex]s_{M_d}=\sqrt{\dfrac{\sigma_1^2}{n_1}+\dfrac{\sigma_2^2}{n_2}}=\sqrt{\dfrac{2.2^2}{26}+\dfrac{4.3^2}{26}}\\\\\\s_{M_d}=\sqrt{0.186+0.711}=\sqrt{0.897}=0.9473[/tex]
The critical t-value for a 99% confidence interval is t=2.678.
The margin of error (MOE) can be calculated as:
[tex]MOE=t\cdot s_{M_d}=2.678 \cdot 0.9473=2.537[/tex]
Then, the lower and upper bounds of the confidence interval are:
[tex]LL=M_d-t \cdot s_{M_d} = -9.4-2.537=-11.937\\\\UL=M_d+t \cdot s_{M_d} = -9.4+2.537=-6.863[/tex]
The 99% confidence interval for the difference between the true average load for the fiberglass beams and that for the carbon beams is (-11.937, -6.863).
In this way, we can calculate the individual duration of each one and the duration time, knowing that the sample means:
The 99% confidence interval for the difference between the true average load for the fiberglass beams and that for the carbon beams is -11.937 and -6.863.
We have to calculate a 99% confidence interval for the difference between the true average load for the fiberglass beams and that for the carbon beams. The sample 1 (Fiberglass), of size n1=26 has a mean of 33.4 and a standard deviation of 2.2. The sample 2 (Carbon), of size n2=26 has a mean of 42.8 and a standard deviation of 4.3. The difference between sample means is Md=-9.4.
[tex]Sm_d= \sqrt{\frac{\sigma^2_1}{n_1} +\frac{\sigma^2_2}{n_2}} = \sqrt{(0.186)+(0.711) }= 0.9473[/tex]
The critical t-value for a 99% confidednce interval is t=2.678. The margin of error (MOE) can be calculated as:
[tex]MOE=t*8M_d = (2.678)(0.9473)= 2.537[/tex]
Then, the lower and upper bounds of the confidence interval are:
[tex]LL= M_d-t*SM_d = -9.4-2.537= -11.937\\UL= M_d+t*SM_d= -9.4+2.537= -6.863[/tex]
The 99% confidence interval for the difference between the true average load for the fiberglass beams and that for the carbon beams is (-11.937, -6.863).
See more about statistics at brainly.com/question/2289255