Answer:
y - x= - 13 -------(1)
- 4x + 3y = -51 -------(2)
(1) => y = - 13 + x
Substitute y in (2)
- 4x + 3( - 13 + x) = -51
- 4x - 39 + 3x = -51
- x = -51 + 39
- x = -12
x = 12
Substitute x in (1)
y = - 13 + x = -13 + 12 = - 1
x = 12, y = -1
Fifteen students from Poppy High School were accepted at Branch University. Of those students, six were offered academic scholarships and nine were not. Mrs. Bergen believes Branch University may be accepting students with lower ACT scores if they have an academic scholarship. The newly accepted student ACT scores are shown here.
Academic scholarship: 25, 24, 23, 21, 22, 20
No academic scholarship: 23, 25, 30, 32, 29, 26, 27, 29, 27
Part A: Do these data provide convincing evidence of a difference in ACT scores between students with and without an academic scholarship? Carry out an appropriate test at the α = 0.02 significance level. (5 points)
Part B: Create and interpret a 98% confidence interval for the difference in the ACT scores between students with and without an academic scholarship. (5 points)
Answer:
See below for answers and explanations
Step-by-step explanation:
Part A:
Given:
Pooled sample size: [tex]n=15[/tex]
Sample size (with academic scholarships): [tex]n_1=6[/tex]
Sample size (no academic scholarships): [tex]n_2=9[/tex]
Population standard deviations: Unknown
Sample mean (with academic scholarships): [tex]\bar{x}=\frac{25+24+23+21+22+20}{6}=22.5[/tex]
Sample mean (no academic scholarship):[tex]\bar{x}=\frac{23+25+30+32+29+26+27+29+27}{9}=27.\bar{5}[/tex]
Sample standard deviation (with academic scholarships): [tex]s_1=1.7078[/tex]
Sample standard deviation (no academic scholarships): [tex]s_2=2.5868[/tex]
Degrees of freedom: [tex]df=n-2=15-2=13[/tex]
Significance level: [tex]\alpha =0.02[/tex]
Decide which test is most appropriate to conduct:
Therefore, we will conduct a 2-sample t-test assuming our conditions are satisfied.
List null and alternate hypotheses:
[tex]H_o:\mu_1=\mu_2[/tex] -> There's no difference in ACT scores between students with and without an academic scholarship
[tex]H_a:\mu}_1\neq\mu_2[/tex] -> There's a difference in ACT scores between students with and without an academic scholarship (it's two-sided)
Determine the value of the test statistic:
We will use the formula [tex]t=\frac{\bar{x}_1-\bar{x}_2}{\sqrt{\frac{s_1^2}{n_1}+\frac{s_2^2}{n_2} } }[/tex] to compute the test statistic [tex]t[/tex]. Therefore, the test statistic is [tex]t=\frac{\bar{x}_1-\bar{x}_2}{\sqrt{\frac{s_1^2}{n_1}+\frac{s_2^2}{n_2} } }=\frac{27.\bar{5}-22.5}{\sqrt{\frac{1.7078^2}{6}+\frac{2.5868^2}{9} } }=4.5592[/tex]
Calculate the p-value:
Because the test is two-sided, [tex]p=2tcdf(4.5592,1e99,13)=2(0.0003)=0.0006[/tex]
Interpret p-value and conclude test:
Given our significance level is [tex]\alpha =0.02[/tex], since [tex]p<\alpha[/tex], we reject the null hypothesis and conclude that there is significant evidence that suggests that there is a difference in ACT scores between students with and without an academic scholarship (it's more likely that the alternate hypothesis is true)
Part B:
The formula for a confidence interval for the difference in 2 population means is [tex]CI=(\bar{x}_1-\bar{x}_2)\pm t^*\sqrt{\frac{s_1^2}{n_1}+\frac{s_2^2}{n_2}}}[/tex] where [tex]\bar{x}_1-\bar{x}_2[/tex] is the difference of the 2 sample means and [tex]t^*[/tex] is the critical score for the desired confidence level.
The critical score for our 98% confidence interval would be [tex]t^*=invT(0.99,13)=2.6503[/tex]
Therefore, our 98% confidence interval for the difference in the ACT scores between students with and without an academic scholarship is [tex]CI=(27.\bar{5}-22)\pm 2.6503\sqrt{\frac{1.7078^2}{6}+\frac{2.5868^2}{9}}}=[2.6167,8.4944][/tex]
This means that we are 98% confident that the true difference in the ACT scores between students with and without an academic scholarship is contained within the interval [tex][2.6167,8.4944][/tex]
The evaluation of sub-parts results in:
Part A: Yes, the data provides convincing evidence of a difference in A at CT scores between students with and without an academic scholarship at α = 0.02
Part B: The 98% confidence interval for the difference in the ACT scores between students with and without an academic scholarship is evaluated to be [tex]CI \approx [-7.00, -2.14][/tex]
How to perform two sample t-test?If the sample sizes < 30, and we want to test the difference between the sample means, then we perform t-test.
Let we have:
[tex]\overline{x}_1[/tex] = mean of first sample[tex]\overline{x}_2[/tex] = mean of second sample[tex]s_1[/tex] = standard deviation of first sample[tex]s_2[/tex] = standard deviation of second sample.Then, the value of t-test statistic is obtained as:
[tex]t = \dfrac{\overline{x}_1 - \overline{x}_2}{\sqrt{\dfrac{s_1^2}{n_1} + \dfrac{s_2^2}{n_2}}}[/tex]
If the level of significance is [tex]\alpha[/tex], then as we have:
the degree of freedom (d.f) = [tex]n_1 + n_2 - 2[/tex], the critical value of t is found to be [tex]t_{\alpha/2}[/tex], then if we get:
[tex]|t| < t_{\alpha/2}[/tex]null hypothesis
and if we get [tex]|t| > t_{\alpha/2}[/tex] null hypothesis, and thus, accept the alternate hypothesis.
For this case, we want to test if there is
Thus, we form the hypotheses as:
Null hypothesis: There's no difference in ACT scores between students with and without an academic scholarship
or: [tex]H_0: \mu_1 = \mu_2[/tex]
Alternative hypothesis: There's a difference in ACT scores between students with and without an academic scholarship (it's two-sided)
or [tex]H_1: \mu_1 \neq \mu_2[/tex]
where we have:
[tex]\mu_1[/tex] = population mean score of ACT of students having academic scholarship[tex]\mu_2[/tex] = population mean score of ACT of students having no academic scholarshipFor this case, we evaluate the mean and standard deviation as:
Sample 1: Academic scholarship: 25, 24, 23, 21, 22, 20Sample size = [tex]n_1 = 6[/tex]
Mean = sum of all observation/ number of observations = 135/6 =22.5
Thus, standard deviation = [tex]s_1 = \sqrt{\dfrac{1}{n}\sum{(x_i - \overline{x_1})^2}} = \sqrt{\dfrac{17.5}{6}} \approx1.71[/tex]
Sample 2: No academic scholarship: 23, 25, 30, 32, 29, 26, 27, 29, 27Sample size = [tex]n_2 = 9[/tex]
Mean = sum of all observation/ number of observations = 248/9 ≈27.56
Thus, standard deviation = [tex]s_2 = \sqrt{\dfrac{1}{n}\sum{(x_i - \overline{x_2})^2}} \approx \sqrt{\dfrac{60.22}{9}} \approx 2.59[/tex]
The t-test statistic is evaluated as:
[tex]t = \dfrac{\overline{x}_1 - \overline{x}_2}{\sqrt{\dfrac{s_1^2}{n_1} + \dfrac{s_2^2}{n_1}}} = \dfrac{22.5 -27.56}{\sqrt{\dfrac{2.92}{6} + \dfrac{6.69}{9}}} \approx -4.56[/tex]
Degree of freedom = [tex]n_1 + n_2 - 2 = 6 + 9 - 2 = 13[/tex]
Level of significance = 0.02 = 2%
The critical value of t is found to be [tex]t_{0.02/2} =2.65[/tex]
Thus, we get: [tex]|t| \approx 4.56 > 2.65 =t_{\alpha/2}[/tex]
Thus, we may reject the null hypothesis.
That means, there is enough evidence of a difference in ACT scores between students with and without an academic scholarship at 0.02 level of significance.
Now, the 98% confidence interval for the difference in the ACT scores between students with and without an academic scholarship is calculated as:
[tex]CI = (\overline{x}_1 - \overline{x}_2) \pm t_{\alpha/2}\sqrt{\dfrac{s_1^2}{n_1} + \dfrac{s_2^2}{n_1}}\\\\CI = -5.06 \pm 2.65(\sqrt{\dfrac{2.92}{6} + \dfrac{6.69}{9}})\\\\CI \approx -5.06 \pm 2.65 \times 1.11\\CI \approx -5.06 \pm 2.94\\CI \approx [-5.06 - 2.94, -5.06 + 2.94] = [-7.00, -2.14][/tex]
Thus, the evaluation of sub-parts results in:
Part A: Yes, the data provides convincing evidence of a difference in A at CT scores between students with and without an academic scholarship at α = 0.02
Part B: The 98% confidence interval for the difference in the ACT scores between students with and without an academic scholarship is evaluated to be [tex]CI \approx [-7.00, -2.14][/tex]
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plz help me asap !!!
Answer:
Step-by-step explanation:
x+60=140
x=140-60
x=80 degree
En un bolsillo tengo una cantidad de dinero y en el otro tengo el doble. En total tengo 600. ¿cuántos euros tengo en cada bolsillo?
Answer:
La cantidad de dinero en:
Primer bolsillo = x = 200 euros
Segundo bolsillo = 2x = 400 euros
Step-by-step explanation:
Nos dijeron:
En un bolsillo tengo una cantidad de dinero y en el otro tengo el doble.
Representemos, la cantidad de dinero en el:
Primer bolsillo = x
Segundo bolsillo = 2x
En total tengo 600.
Por eso:
x + 2x = 600
3 veces = 600
x = 600/3
x = 200
2x = 200 × 2
x = 400
Por lo tanto, la cantidad de dinero en:
Primer bolsillo = x = 200 euros
Segundo bolsillo = 2x = 400 euros
Find the value of x that makes m∥n. PLEASEE HELP
Answer:
Step-by-step explanation:
143=5x+13(being corresponding angles)
143-13=5x
130/5=x
26=x
=======================================================
Explanation:
The angles shown are corresponding angles. Notice how they are in the northeast corner of their respective four-corner configuration.
If m is parallel to n, then the corresponding angles are congruent, and we can say...
5x+13 = 143
5x = 143-13 .... subtract 13 from both sides
5x = 130
x = 130/5 .... divide both sides by 5
x = 26
So taking this logic in reverse: if x = 26, then that leads to 5x+13 equal to 143, making the corresponding angles congruent. Therefore, it would lead to lines m and n being parallel.
And please help me with this one too!! Thank you!!
Answer:
math.way
Step-by-step explanation:
Answer:
Step-by-step explanation:
y^2=49
y=[tex]\sqrt{49}[/tex]
y=7
Assume that you want to construct a box with a square base (closed top) and a volume of 1000 cm3 . Find the dimensions of the box to minimize the surface area of the box.
Answer:
[tex]x=10\sqrt[3]{2}[/tex]
Step-by-step explanation:
The Volume of a box with a square base
x by x cm and height h cm is
V =x^2h
The amount of material used is directly proportional to the surface area, so we will minimize the amount of material by minimizing the surface area.
The surface area of the box described is
A = x ^2 +4 x h
We need
A as a function of x alone, so we'll use the fact that
V= x^2h = 1000 cm^3
This imples [tex]h=\frac{1000}{x^2}[/tex]
This makes
[tex]A= x^2 + 4x(1000/x^2)\\A= x^2+4000/x[/tex]
Differentiating A w.r.t. x
[tex]A' = 2x-4000/x^2[/tex]
Now, A'=0
[tex]x=10\sqrt[3]{2}[/tex]
Therefore, minimum value x = [tex]x=10\sqrt[3]{2}[/tex]
1. Gwen deposits $7,000 in a savings account with an annual interest rate of 2.5%. What function
represents the value of her account after x years? What will her balance be after 9 years?
Answer:
Results are below.
Step-by-step explanation:
Giving the following information:
Initial investment (PV)= $7,000
Interest rate (i)= 2.5%
To calculate the future value after x years, we need to use the following formula:
FV= PV*(1 + i)^x
Now, for 9 years:
x= 9
FV= 7,000*(1.025^9)
FV=$8,742.04
please help ASAP! 7th grade
Since their were no numbers to the questions i had to write it by the problem
Circle with 9 feet question
C=2(pi)r or C=(pi)d
Circular table question
A=(pi)r^2
Interest question
I=Prt
Volume of a rectangular prism
V=Bh
Triangular pyramid
V=1/3Bh
Match the vocabulary word with the correct definition.
1. compound event
2. independent event
3. dependent event
- the occurrence of one event affects
the probability of the occurrence of another event
- the occurrence of one event does
not affect the probability of the occurrence of another event
- two or more events considered
independent event-the occurrence of one event does not affect the probability of the occurrence of another event
compound event-two or more events considered
dependent event-the occurrence of one event affects the probability of the occurrence of another event
a) Compound Event refers to the combination of two or more events considered.
b) Independent Event occurs when one event does not affect the probability of the occurrence of another event.
c) Dependent Event describes a situation where the occurrence of one event affects the probability of the occurrence of another event
a) Compound Event: This refers to the combination of two or more events considered together. It involves analyzing the probability of multiple events occurring in a specific situation or experiment. For example, when rolling a pair of dice, the compound event might be the probability of getting a sum greater than 9.
b) Independent Event: This occurs when the outcome or occurrence of one event has no impact on the probability of the outcome or occurrence of another event. In other words, the events are unrelated and do not influence each other. For example, flipping a coin and rolling a die are independent events since the outcome of the coin flip does not affect the outcome of the die roll.
c) Dependent Event: This describes a situation where the occurrence of one event does affect the probability of the occurrence of another event. In dependent events, the outcome or happening of the first event has an impact on the likelihood of the second event. For instance, drawing cards from a deck without replacement is a dependent event since the probability of drawing a certain card changes after each card is drawn.
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Which symbol correctly compares the two angles?
45° pi/3
Answer:
a pi = 3.14
Step-by-step explanation:
The symbol which compares the two angles is "< ".
What is an angle?
Angles around a point define the sum of angles that can be arranged together so that they construct a full arch. Angles around a point add to 360 °.
π/3 =180/3 = 60 degree
π/3 > 45 degree
45 degree < π/3
Therefore, the correct answer is option A. <.
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What's the mean of {4,7,10}
Answer:
mean = (4 + 7 + 10 ) / 3
= 21 / 3
= 7
Step-by-step explanation:
Answer:
Average of 4,7 and 10:
Add all together 4+7+10=21
Then 21 divided by number of scores so 3.
21 divided by 3=7
So the mean is 7
Can someone please help me?
A point is on a circle if the distance from the center of the circle to the point is equal to the
area.
circumference.
radius.
diameter
Answer:
radius
Step-by-step explanation:
Answer:
Radius
Step-by-step explanation:
Center of the circle to a point on a circle would be the radius, seeing how as diameter is one edge of the circle to the other edge,of the circle, crossing the middle of the circle
what is the area of B1, =4,B2 =8, h =2
Answer: 12
Step-by-step explanation:
At Sam’s Warehouse, a member pays $25 a year for a membership, and then buys all products at the regular store prices. A non-member does not pay the membership fee, but does pay an additional 5% above the store prices. Write and solve a system of equations to represent this situation where is the store price and is the total amount paid.xy
Answer:
[tex]y = 25 + x[/tex] --- Members
[tex]y = 1.05x[/tex] --- Non-members
Step-by-step explanation:
Given
[tex]x \to store\ price[/tex]
[tex]y\to total\ amount[/tex]
Members
[tex]Membership =\$25[/tex]
Non-members
[tex]Rate = 5\%[/tex] increase
For the members, the equation is:
[tex]y = Membership + Store\ price[/tex]
[tex]y = 25 + x[/tex]
For non-members, the equation is:
[tex]y = Store\ price * (1 + Rate)[/tex]
[tex]y = x * (1 + 5\%)[/tex]
[tex]y = x * (1.05)[/tex]
[tex]y = 1.05x[/tex]
3
Find the missing angle.
20
180°
A
100°
B
50°
80°
D 70°
The larger of two numbers is 15 more than three times the smaller number. If the sum of the two numbers is 63, find the numbers.
pls help will give brainliest
Answer:
132
Step-by-step explanation:
Volume for a rectangular prism is V=lwh. so you do 11*3*4. 11 is the length, 3 is the width and 4 is the height
Answer:
uhh, look it up
Step-by-step explanation:
Hey help me out please?
Answer:
I believe it is C
It's the only one that makes sense
One solution to a quadratic equation is 4 - 5i. Find the equation.
Answer:
The answer would be Equation B:
x2 - 8x + 41
Step-by-step explanation:
y = 3x2 – 2x +3
Please help
Answer:
[tex]y = {3x}^{2} - 2x + 3 \\ y = ( \frac{1}{3} + i) {}^{2} [/tex]
Three families, a, b, & c share 480 kg of rice. B receives twice as much as a, c receives half of b. How much rice does each family get?
Answer:
Family a got 120kg, b got 240 kg and c got 120 kg
Step-by-step explanation:
Given that 480kg of rice is shared by families a, b, c. let these alphabets represent the amount received by each family.
a + b + c = 480
Given that B receives twice as much as a, c receives half of b then,
b = 2a and
c = 1/2 b = b/2
from b = 2a,
a = b/2
substituting into the first equation
b/2 + b + b/2 = 480
b + b = 480
2b = 480
b = 480/2
= 240 kg
a = c = b/2
hence a = c = 240/2 = 120kg
Find the area of the shaded region.
Answer:
12.86 sq ft
Step-by-step explanation:
Find area of square and subtract out area of semi-circle; the diameter of the semi-circle equals the side of the square, which is 4 so radius is 2
A(square) = 4 x 4 = 16
A(semi-circle) = πr²/2
= 4π/2 or 2π
Area of Shaded Region = 16-3.14 which is 12.86
Hellppp pleaseee
Please be quick lol
Answer:
20(pi)
Step-by-step explanation:
• equation for the circumference of a circle= 2(pi)r
• You are given the diameter ( 20ft) but you need the radius (r) for the equation.
• divide 20 by 2 to get the radius since it is half of the diameter.
• 20/2=10 so c= 2(pi)(10)
• 2(10)=20
• plug in pi and your final answer is 20(pi)
Aiden uses 1/6 cup of blue paint for every 1/2 cup of red paint to make purple paint what is the number of cups of blue paint aiden uses for 1 cup of red paint
Answer:
your answer is 2/6 or 1/3 a cup.
Step-by-step explanation:
A ship from Port travels fot 60km on the bearing of 129°.It continues to travel and changes direction for another 50km on a bearing of 080°
Answer:
The ship is approximately 100 km to the Port.
Step-by-step explanation:
The sketch to the question gives a triangle with two sides and an included angle. Let the distance from the Port to the stopping point of the ship be represented by c. It can be determined by the application of cosine rule. Cosine rule states that:
[tex]c^{2}[/tex] = [tex]a^{2}[/tex] + [tex]b^{2}[/tex] -2ab Cos C
a = 50 km
b = 60 km
C = 51 + 80 = [tex]131^{o}[/tex]
So that;
[tex]c^{2}[/tex] = [tex]50^{2}[/tex] + [tex]60^{2}[/tex] -2(50 x 60) Cos [tex]131^{o}[/tex]
= 2500 + 3600 -6000 x -0.6561
= 6100 + 3936.6
[tex]c^{2}[/tex] = 10036.6
c = [tex]\sqrt{10036.6}[/tex]
= 100.183
c = 100.18 km
Thus, the ship is approximately 100 km to the Port.
I NEED THIS ASAP. I WILL GIVE ALL MY 32 POINTS
MY ASSESMENT IS DUE TOMMOROW AND I HAVEN'T STARTED AND I NEED FULL MARKS
ANY QUESTIONS PLEASE COMMENT THANKS
Hi I can help u if you want to!!!
Can someone help me with this thank you
Answer:
30 sq cm
Step-by-step explanation:
The area of a parallelogram is the base times the height. We can see that the base is 10 cm, and 3 cm would be the height because it is perpendicular to the base. We get the equation:
Area = 10 cm x 3 cm
Area = 30 sq cm
1,367.5897 to the nearest whole
Answer:
1368
hope this helps
have a good day :)
Step-by-step explanation:
p-8=3 can some one help me
Answer:
p=3+8=11
Step-by-step explanation:
Answer:
p = 11
Step-by-step explanation:
add 8 to both sides of the equation, so p = 3 + 8
p = 11