Answer:
Option A.
Step-by-step explanation:
The given equation of ellipse is
[tex]4x^2+9y^2=36[/tex]
Divide both sides by 36.
[tex]\dfrac{4x^2}{36}+\dfrac{9y^2}{36}=1[/tex]
[tex]\dfrac{x^2}{9}+\dfrac{y^2}{4}=1[/tex]
[tex]\dfrac{x^2}{3^2}+\dfrac{y^2}{2^2}=1[/tex] ...(1)
The standard form of an ellipse is
[tex]\dfrac{(x-h)^2}{a^2}+\dfrac{(y-k)^2}{b^2}=1[/tex] ...(2)
where, (h,k) is center, (h±a,k) are vertices and (h±c,k) are foci.
On comparing (1) and (2), we get
[tex]h=0,k=0,a=3,b=2[/tex]
Now,
Center [tex]=(h,k)=(0,0)[/tex]
Vertices [tex]=(h\pm a,k)=(0\pm 3,0)=(3,0),(-3,0)[/tex]
We know that
[tex]c=\sqrt{a^2-b^2}=\sqrt{3^2-2^2}=\sqrt{5}[/tex]
Foci [tex]=(h\pm c,k)=(0\pm \sqrt{5},0)=(\sqrt{5},0),(-\sqrt{5},0)[/tex]
Therefore, the correct option is A.
Which represents a measure of volume?
O 5 cm
O 5 square cm
05 cm
05 cm
Answer:
a) 5[tex]cm^{3}[/tex]
Step-by-step explanation:
Bodies have three dimensions (width, height and depth). Measuring volume is calculating the number of cubic units that can fit inside.
When raising to 3, these dimensions are included and therefore 5[tex]cm^{3}[/tex] is a measure of volume.
Answer:
5cm^3
Step-by-step explanation:
Volume for a form will always be in cubic units.
Area of a shape will always be in squared units.
Length will not be in cubic or squared units.
Hence, the first option is a measure for volume.
The second option is equal to 5cm^2 which represents a measure for area, as does the fourth option.
The third option represents a measurement of length, for example the length of a line segment or the height of a figure.
Can your help me please?
Answer:
(-5, 0) and (0,4)
Step-by-step explanation:
Given equation: -4x + 5y = 20
Sub. in the values
When x = -5 and y = 0 (-5,0),
[tex] - 4( - 5) + 5(0) = 20 [/tex]
When x = 0 and y = 4 (0,4),
[tex] - 4(0) + 5(4) = 20[/tex]
That's how I would do it, not sure if your school has another method. Hope this helps :)
Answer: x = -5 and y = 4
Step-by-step explanation: its the first option do you need me to exlain how cuz its multiple choice
The number of values of xx in the interval [0,5π][0,5π] satisfying the equation 3sin2x−7sinx+2=03sin2x-7sinx+2=0 is/are
Answer:
6
Step-by-step explanation:
Given, 3sin2x−7sinx+2=03sin2x-7sinx+2=0
⇒(3sinx−1)(sinx−2)=0⇒3sinx-1sinx-2=0
⇒sinx=13 or 2⇒sinx=13 or 2
⇒sinx=13 [∵sinx≠2]⇒sinx=13 [∵sinx≠2]
Let sinα=13,0<α<π2,sinα=13,0<α<π2, then sinx=sinαsinx=sinα
now x=nπ+(−1)nα(n∈I)x=nπ+(−1)nα(n∈I)
⇒x=α,π−α,2π+α,3π−α,4π+α,5π−α⇒x=α,π−α,2π+α,3π−α,4π+α,5π−α Are the solution in [0,5π][0,5π]
Hence, required number of solutions are 6
This table shows a linear relationship.
The slope of the line is ?
Answer:
2
Step-by-step explanation:
2,8 to 4,12 has a rise of 4 and a run of 2.
4/2 = 2
The slope is 2.
Remember rise/run!
Answer:
2
Step-by-step explanation:
We take take two points and use the slope formula
m = (y2-y1)/(x2-x1)
m = (12-8)/(4-2)
= 4/2
= 2
Evaluate the expression for q = -2. 8q=
Answer:
-16
Step-by-step explanation:
8q
Let q = -2
8*-2
-16
PLEASE HELP QUICK!!!!!!! Find the length of a rectangle that has one side of length 8 and area 32
Answer:
4
Step-by-step explanation:
Length of one side=8
Area=32
Length of another side=x
8 into x = 32
X=32/8
=4
A person tosses a fair coin until a tail appears for the first time. If the tail appearson thenth flip, the person winsndollars. LetXdenote the player’s winnings.ComputeE(X).
Answer: The answer in a is No while the answer in b is Yes
Step-by-step explanation:
Find the explanation in the attached file.
36 minus 20 minus 32 times 1/4
Answer:
6
Step-by-step explanation:
36 - 20 - 32 x 1/4
=> 36 - 20 - 32/4
=> 36 - 20 - 8
=> 36 - 28
=> 6
Help please anyone. Thank You
Answer:
A) 144 yd²
Step-by-step explanation:
Base= 8x8=64
Side = 1/2*8*5=20
64+20+20+20+20=144 yd²
Answer:
168 sq yds
Step-by-step explanation:
5x8/2x2=40
8x8/2x2=64
8x8=64
40+64+64=168
If x =y, then x-a=y-a represents the blank property of equality. A-addition B-symmetric C-subtraction D.transitive
Answer:
Subtraction property
Step-by-step explanation:
Answer:
Subtraction
Step-by-step explanation:I took the test
I need help badly best answer gets BRAINLIEST:)
Answer:
a = 55°, b = 65°, c = 65°, d = 60°, e = 120°, f = 60°
Step-by-step explanation:
Vertical angles are congruent. Since a and 55° are vertical angles, we know that a = 55°. Since b and 65° are vertical angles, we know that b = 65°. Alternate interior angles are congruent. Since b and c are alternate interior angles and b = 65°, we know that c = 65° as well. Since 60° and d are alternate interior angles, we know that d = 60°. Supplementary angles add up to 180°. Since d and e are supplementary and d = 60°, we know that e = 180 - 60 = 120°. Since vertical angles are congruent, we see that d and f are vertical angles and we know d = 60°, we also know that f = 60°.
Look at parallelogram below d1 and d3 Are both 35 degrees what is the measurement of d2
Answer:
145 degrees
Step-by-step explanation:
Adjacent angles in a parallelogram are supplementary.
d2 = 180° -d1 = 180° -35°
d2 = 145°
Give this problem a try and try to solve this
Answer:
No solution
Step-by-step explanation:
Given equation is,
[tex]\frac{x^{\frac{1}{2}}+x^{-\frac{1}{2}}}{1-x}+\frac{1-x^{-\frac{1}{2}}}{1+x^\frac{1}{2}}-\frac{(4+x)^\frac{1}{2}}{(1-x)^\frac{1}{2}}=0[/tex]
[tex]\frac{x^{\frac{1}{2}}+x^{-\frac{1}{2}}}{1-x}+\frac{1-x^{-\frac{1}{2}}}{1+x^\frac{1}{2}}=\frac{(4+x)^\frac{1}{2}}{(1-x)^\frac{1}{2}}[/tex]
[tex]\frac{(x+1)}{\sqrt{x}(1-x)}+\frac{(\sqrt{x}-1)}{\sqrt{x}(1+\sqrt{x})}=(\frac{4+x}{1-x})^{\frac{1}{2}}[/tex]
[tex]\frac{(\sqrt{x}+1)(x+1)+(\sqrt{x}-1)(1-x)}{\sqrt{x}(1-x)(1+\sqrt{x})}=(\frac{4+x}{1-x})^{\frac{1}{2}}[/tex]
[tex]\frac{x\sqrt{x}+x+\sqrt{x}+1+\sqrt{x}-1-x\sqrt{x}+x}{\sqrt{x}(1-x)(1+\sqrt{x})}=(\frac{4+x}{1-x})^\frac{1}{2}[/tex]
[tex]\frac{2x+2\sqrt{x}}{\sqrt{x}(1-x)(1+\sqrt{x})}=(\frac{4+x}{1-x})^\frac{1}{2}[/tex]
[tex]\frac{2(\sqrt{x}+1)}{(1-x)(1+\sqrt{x})}=(\frac{4+x}{1-x})^\frac{1}{2}[/tex]
[tex]\frac{2}{1-x}=(\frac{4+x}{1-x})^\frac{1}{2}[/tex] if x ≠ ±1
[tex](\frac{2}{1-x})^2=\frac{4+x}{1-x}[/tex] [Squaring on both the sides of the equation]
[tex]\frac{4}{(1-x)}=(4+x)[/tex]
4 = (1 - x)(4 + x)
4 = 4 - 4x + x - x²
0 = -3x - x²
x² + 3x = 0
x(x + 3) = 0
x = 0, -3
But both the solutions x = 0 and x = -3 are extraneous solutions, given equation has no solution.
Answer:
Could you please help me Genius??????
Given the following three points, find by the hand the quadratic function they represent (0,6, (2,16, (3,33)
Answer:
[tex] f(x) = 4x^2 - 3x + 6 [/tex]
Step-by-step explanation:
Quadratic function is given as [tex] f(x) = ax^2 + bx + c [/tex]
Let's find a, b and c:
Substituting (0, 6):
[tex] 6 = a(0)^2 + b(0) + c [/tex]
[tex] 6 = 0 + 0 + c [/tex]
[tex] c = 6 [/tex]
Now that we know the value of c, let's derive 2 system of equations we would use to solve for a and b simultaneously as follows.
Substituting (2, 16), and c = 6
[tex] f(x) = ax^2 + bx + c [/tex]
[tex] 16 = a(2)^2 + b(2) + 6 [/tex]
[tex] 16 = 4a + 2b + 6 [/tex]
[tex] 16 - 6 = 4a + 2b + 6 - 6 [/tex]
[tex] 10 = 4a + 2b [/tex]
[tex] 10 = 2(2a + b) [/tex]
[tex] \frac{10}{2} = \frac{2(2a + b)}{2} [/tex]
[tex] 5 = 2a + b [/tex]
[tex] 2a + b = 5 [/tex] => (Equation 1)
Substituting (3, 33), and c = 6
[tex] f(x) = ax^2 + bx + x [/tex]
[tex] 33 = a(3)^2 + b(3) + 6 [/tex]
[tex] 33 = 9a + 3b + 6 [/tex]
[tex] 33 - 6 = 9a + 3b + 6 - 6 [/tex]
[tex] 27 = 9a + 3b [/tex]
[tex] 27 = 3(3a + b) [/tex]
[tex] \frac{27}{3} = \frac{3(3a + b)}{3} [/tex]
[tex] 9 = 3a + b [/tex]
[tex] 3a + b = 9 [/tex] => (Equation 2)
Subtract equation 1 from equation 2 to solve simultaneously for a and b.
[tex] 3a + b = 9 [/tex]
[tex] 2a + b = 5 [/tex]
[tex] a = 4 [/tex]
Replace a with 4 in equation 2.
[tex] 2a + b = 5 [/tex]
[tex] 2(4) + b = 5 [/tex]
[tex] 8 + b = 5 [/tex]
[tex] 8 + b - 8 = 5 - 8 [/tex]
[tex] b = -3 [/tex]
The quadratic function that represents the given 3 points would be as follows:
[tex] f(x) = ax^2 + bx + c [/tex]
[tex] f(x) = (4)x^2 + (-3)x + 6 [/tex]
[tex] f(x) = 4x^2 - 3x + 6 [/tex]
Solve the following equations
x-1=6/x
[tex]x-1=\dfrac{6}{x}\qquad(x\not=0)\\\\x^2-x=6\\x^2-x-6=0\\x^2+2x-3x-6=0\\x(x+2)-3(x+2)=0\\(x-3)(x+2)=0\\x=3 \vee x=-2[/tex]
The average age of a part-time seasonal employee at a Vail Resorts ski mountain has historically been 37 years. A random sample of 50 part-time seasonal employees in 2010 had a mean of 38.5 years with a standard deviation of 16 years. Required:a. At the 5 percent level of significance, does this sample show that the average age was different in 2010? b. Which is the right hypotheses to test the statement?c. What are the test statistic and critical value?
Answer:
No the sample does not show that the average age was different in 2010
Step-by-step explanation:
From the question we are told that
The sample size is n = 50
The sample mean is [tex]\= x = 38.5[/tex]
The population mean is [tex]\mu = 37[/tex]
The standard deviation is [tex]\sigma = 16[/tex]
The level of significance is [tex]\alpha = 5 \% = 0.05[/tex]
The null hypothesis is [tex]H_o : \mu = 37[/tex]
The alternative hypothesis is [tex]H_a : \mu \ne 37[/tex]
The critical value of the level of significance obtained from the normal distribution table is ([tex]Z_{\alpha } = 1.645[/tex] )
Generally the test statistics is mathematically evaluated as
[tex]t = \frac{ \= x - \mu }{ \frac{\sigma }{\sqrt{n} } }[/tex]
substituting values
[tex]t = \frac{ 38.5 - 37}{ \frac{16}{\sqrt{50} } }[/tex]
[tex]t = 0.663[/tex]
Now looking at the value t and [tex]Z_{\alpha }[/tex] we see that [tex]t < Z_{\alpha }[/tex] hence we fail to reject the null hypothesis.
This mean that there is no sufficient evidence to state that the sample shows that the average age was different in 2010
Subtract 5p + 8q from the sum of 5p + 4q and – 9p + 69.
Answer:
-9p -4q + 69
Step-by-step explanation:
5p +4q + (-9p +69)
=> 5p + 4q -9p +69
=> -4p +4q +69
Now, we need to subtract 5p +8q from -4p + 4q +69
=> -4p +4q +69 - (5p +8q)
=> -4p + 4q +69 - 5p -8q
=> -9p -4q + 69
Let s1 = k and define sn+1 = √4sn − 1 for n ≥ 1. Determine for what values of k the sequence (sn) will be monotone increasing and for what values of k it will be monotone decreasing.
Answer:
The answer is "[tex]\bold{\frac{1}{4}<k\leq 2+\sqrt{3}}[/tex]"
Step-by-step explanation:
Given:
[tex]\ S_1 = k \\\\ S_{n+1} = \sqrt{4S_n -1}[/tex] [tex]_{where} \ \ n \geq 1[/tex]
In the above-given value, [tex]S_n[/tex] is required for the monotone decreasing so, [tex]S_2 :[/tex]
[tex]\to \sqrt{4k-1} \leq \ k=S_1\\\\[/tex]
square the above value:
[tex]\to k^2-4k+1 \leq 0\\\\\to k \leq 2+\sqrt{3} \ \ \ \ \ and \ \ 4k+1 >0\\\\[/tex]
[tex]\bold{\boxed{\frac{1}{4}<k\leq 2+\sqrt{3}}}[/tex]
The average of 4 numbers is 15 , the sum of 3 numbers is 14 what is the fourth number
Answer:
46
Step-by-step explanation:
(14+x)/4 = 15
14 + x = 60
x = 46
Answer:
46
Step-by-step explanation:
Let a to d be number 1 to 4 respectively.
15 = (a + b + c + d) / 4
(a + b + c + d) = 60 ------> total sum of the 4 numbers
Since the sum of 3 numbers (assuming a to c) is 14,
Fourth number (d) = 60 - 14
= 46
That's how I would do it, hope this helps :)
Find the length of FT¯¯¯¯¯¯¯ A. 77.71 B. 72.47 C. 56.84 D. 49.42
Answer:
D, 49.42
Step-by-step explanation:
ΔVFT=180-90-43=47
formula
a/sin A = b/sin B/ = c/sin C
So,
FV/sin90=53/sin47
FV=72.4684
FT=√(72.4684)^2-(53)^2
FT=49.4234
Ans:D
The length FT in the given right-angle triangle is 49.42.
So option D is the correct answer.
We are given a right-angle triangle and to find the length of any side we can use Pythagoras theorem or trigonometric identities.
In the triangle, we see that TV = 53 and ∠ FVT = 43°
We will find the length FT by using Pythagoras theorem or trigonometric identities.
What are trigonometric functions?
There are some commonly used trigonometric identities:
SinФ = Perpendicular / hypotenuse
Cos Ф = Base / hypotenuse
Tan Ф = Perpendicular / Base
We will use Tan Ф = Perpendicular / Base to find the length FT.
Because we need to use trigonometric identities that have TV and FT.
Tan Ф = FT / TV
Tan 43° = FT / 53
FT = Tan 43° x 53
FT = 0.932515 X 53
FT = 49.42
Thus we got FT = 49.42 using the tan function.
Learn more about trigonometric functions here:
https://brainly.com/question/14746686
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URGENT, PLEASE HELP! (3/5) -50 POINTS- !please no wrong answers for the points.! A) [tex]y = \frac{9}{2} x + \frac{1}{2}[/tex] B) [tex]y = - \frac{1}{2} x + \frac{7}{2}[/tex] C) [tex]y = -4x + 9[/tex] D) [tex]y = 4x + 15[/tex]
Answer:
B y = -1/2x + 7/2
Step-by-step explanation:
We know that it has a negative slope since the points go from the top left to the bottom right
We can eliminate A and D
The y intercept is where it crosses the y axis
It should cross somewhere between 2 and 4
C has a y intercept of 9 which is too big
Lets verify with a point
x = -4
y = -4(-4)+9 = 16+9 = 25 (-4,25) not even close to being near the points on the graph
checking B
y = -1/2 (-4) +7/2
= 2 + 7/2 = 11/2 = 5.5 it seems reasonable
Answer:
[tex]\Large \boxed{y=-\frac{1}{2} x+\frac{7}{2} }[/tex]
Step-by-step explanation:
Using a graph,
we can see that the line y = -1/2x + 7/2 best fits for the data.
C-Spec, Inc., is attempting to determine whether an existing machine is capable of milling an engine part that has a key specification of 4 ± .003 inches. After a trial run on this machine, C-Spec has determined that the machine has a sample mean of 4.001 inches with a standard deviation of .002 inch. Calculate the Cpk for this machine.
Answer:
0.3333
Step-by-step explanation:
Given the following :
Sample mean(m) = 4.001 inch
Standard deviation(sd) = 0.002 inch
Key specification : = 4 ± .003 inches
Upper specification LIMIT ( USL) : (4 + 0.003) = 4.003 inches
Lower specification limit (LSL) : (4 - 0.003) = 3.997 inches
Cpk is found using the relation:
min[(USL - mean) / (3 * sd), (mean-LSL) / (3*sd)]
min[(4.003 - 4.001)/(3*0.002), (4.001 - 3.997)/(3*0.002)]
min[(0.002 / 0.006), (0.004 / 0.006)]
min[(0.33333, 0.66667)
Therefore Cpk = 0.3333
Because 0.33333<0.66667
Avi's pet hamster Chubby loves to run in his hamster wheel. During one "race", Avi counts 100100100 rotations of the wheel. She wants to know how far Chubby ran, so she measures the diameter of the wheel and finds that it is 20 \text{ cm}20 cm20, start text, space, c, m, end text. How far did Chubby run? Round your answer to the nearest \text{cm}cmstart text, c, m, end text.
Answer:
63 cm
Step-by-step explanation:
If Chubby ran his wheel, which has a diameter of 20cm, we want to find its circumference - this will tell us how far Chubby has ran one one full rotation of the wheel.
The formula for the circumference of a circle is [tex]2\pi r[/tex], where r is the radius. We know the diameter is 20, which is double the radius, so the radius is [tex]20\div2=10[/tex] cm.
We can know substitute inside the formula:
[tex]2\cdot \pi \cdot10\\\\2\cdot 3.14 \cdot10\\\\ 6.28\cdot10\\\\62.8[/tex]
62.8 rounded to the nearest cm is 63.
Hope this helped!
Answer:
6280
Step-by-step explanation:
a) which function has the graph with the greatest slope?
b) which functions have graphs with y intercepts greater than 3?
c)which function has the graph with a y intercept closest to 0
Answer:
a). Function (4)
b). Function (2)
c). Function (3)
Step-by-step explanation:
Characteristics of the functions given,
Function (1),
Form the given graph,
Slope = [tex]\frac{\text{Rise}}{\text{Run}}[/tex]
= [tex]-\frac{4}{1}[/tex]
= -4
Y- intercept of the given function = 2
Function (2),
From he given table,
Slope = [tex]\frac{y_2-y_1}{x_2-x_1}[/tex]
= [tex]\frac{5-3}{0+1}[/tex]
= 2
y-intercept = 5 [Value of y for x = 0]
Function (3),
y = -x - 1
By comparing this equation with y = mx + b
Where 'm' = slope
and b = y-intercept
Slope = (-1)
y-intercept = (-1)
Function (4),
Slope = 5
y-intercept = (-4)
(a). Greatest slope of the function → Function (4)
(b). y-intercept greater than 3 → Function (2)
(c). Function with y-intercept closest to 0 → Function (3)
The time between consecutive uses of a vending machine is exponential with an average of 15 minutes. a)Given that the machine has not been used in the previous 5 minutes, what is the probability that the machine will not be used during the next 10 minutes
Answer5
Step-by-step explanation:
32. Identify all real and non-real zeros of the function f(x) = x^3 + 5x^2 + 3x + 15.
options:
A. x = 0, −5, 1.7i, −1.7i
B. x = 0,−5, 1.7i
C. x = −5, 1.7i, −1.7i
D. x = 0,−3, −5
Answer:
x = -5 or x = i sqrt(3) or x = -i sqrt(3)
Step-by-step explanation:
Solve for x:
x^3 + 5 x^2 + 3 x + 15 = 0
The left hand side factors into a product with two terms:
(x + 5) (x^2 + 3) = 0
Split into two equations:
x + 5 = 0 or x^2 + 3 = 0
Subtract 5 from both sides:
x = -5 or x^2 + 3 = 0
x = (0 ± sqrt(0^2 - 4×3))/2 = ( ± sqrt(-12))/2:
x = -5 or x = sqrt(-12)/2 or x = (-sqrt(-12))/2
sqrt(-12) = sqrt(-1) sqrt(12) = i sqrt(12):
x = -5 or x = (i sqrt(12))/2 or x = (-i sqrt(12))/2
sqrt(12) = sqrt(4×3) = sqrt(2^2×3) = 2sqrt(3):
x = -5 or x = (i×2 sqrt(3))/2 or x = (-i×2 sqrt(3))/2
(2 i sqrt(3))/2 = i sqrt(3):
x = -5 or x = i sqrt(3) or x = (-2 i sqrt(3))/2
(2 (-i sqrt(3)))/2 = -i sqrt(3):
Answer: x = -5 or x = i sqrt(3) or x = -i sqrt(3)
Answer:
C. x = −5, 1.7i, −1.7i
Step-by-step explanation:
Quick answer:
C. x = −5, 1.7i, −1.7i
explanation:
C. is the only answer option that does NOT have 0 as a root, which is impossible, because there is a constant term, which means that all roots are non-zero. In other words, we cannot extract x as a factor.
Complete answer:
All odd degree polynomials have at least one real root.
By the real roots theorem, we know that
if there is a real root, it must be of the form [tex]\pm[/tex]p/q where q is any of the factors of the leading coefficient (1 in this case) and p is any factor of the constant term d (15 in this case).
Values of [tex]\pm[/tex]p/q are
On trial and error, using the factor theorem, we see that
f(-5) = 0, therefore -5 is a real root. By long division, we have a quotient of x^2+3 = 0, which gives readily the remaining (complex) roots of +/- sqrt(5) i
The answer is {-5, +/- sqrt(5) i}, or again,
C. x = −5, 1.7i, −1.7i
Given the following diagram, find the required measures. Given: l | | m m 1 = 120° m 3 = 40° m 2 = 20 60 120
Step-by-step explanation:
your required answer is 60°.
Hello,
Here, in the figure;
angle 1= 120°
To find : m. of angle 2.
now,
angle 1 + angle 2= 180° { being linear pair}
or, 120° +angle 2 = 180°
or, angle 2= 180°-120°
Therefore, the measure of angle 2 is 60°.
Hope it helps you.....
|3(x–2)|=12 pls help i need assistance
Answer:
x1 = -4
x2 = 6
Step-by-step explanation:
The 2 vertical lines are "absolute values" meaning whatever they contain has to be positive
For Example
|-3| = 3
So we can ignore if the answer we get is positive or negative because it will forced to be a positive
|3 x 4| = 12
|x - 2| = 4
x1 = 6
x2 = -2
Which ordered pair is a solution to the following linear system? y = x y = –x
Answer:
(2,2) (-1,-1)
Step-by-step explanation
i think this is there answer im sorry if im wrong
A study was conducted to assess the effects that occur when children are exposed to cocaine before birth. Children were tested at age 4 for object assembly skill, which was described as a task requiring visual spatial skills related to mathematical competence. The 190 children born to cocaine users had a mean of 7.3 and a standard deviation of 3.0 The 186 children not exposed to cocaine had a mean score of 8.2 with a standard deviation of 3.0 Use a 0.05 significance level to test the claim that prenatal cocaine exposure is associated with lower scores of four year old children on the test of object assembly.
What are null and alternative hypothesis? What is test statistics?
Answer:
We conclude that prenatal cocaine exposure is associated with lower scores of four-year-old children on the test of object assembly.
Step-by-step explanation:
We are given that the 190 children born to cocaine users had a mean of 7.3 and a standard deviation of 3.0 The 186 children not exposed to cocaine had a mean score of 8.2 with a standard deviation of 3.0.
Let [tex]\mu_1[/tex] = population mean score for children born to cocaine users.
[tex]\mu_2[/tex] = population mean score for children not exposed to cocaine.
So, Null Hypothesis, : = 490 {means that the prenatal cocaine exposure is not associated with lower scores of four-year-old children on the test of object assembly}
Alternate Hypothesis, : 490 {means that the prenatal cocaine exposure is associated with lower scores of four-year-old children on the test of object assembly}
The test statistics that will be used here is Two-sample t-test statistics because we don't know about population standard deviations;
T.S. = [tex]\frac{(\bar X_1-\bar X_2)-(\mu_1-\mu_2)}{s_p \times \sqrt{\frac{1}{n_1}+\frac{1}{n_2} } }[/tex] ~ [tex]t__n_1_+_n_2_-_2[/tex]
where, [tex]\bar X_1[/tex] = sample mean score of children born to cocaine users = 7.3
[tex]\bar X_2[/tex] = sample mean score of children not exposed to cocaine = 8.2
[tex]s_1[/tex] = sample standard deviation for children born to cocaine users = 3
[tex]s_2[/tex] = sample standard deviation for children not exposed to cocaine = 3
[tex]n_1[/tex] = sample of children born to cocaine users = 190
[tex]n_2[/tex] = sample of children not exposed to cocaine = 186
Also, [tex]s_p=\sqrt{\frac{(n_1-1)\times s_1^{2}+(n_2-1)\times s_2^{2} }{n_1+n_2-2} }[/tex] = [tex]\sqrt{\frac{(190-1)\times 3^{2}+(186-1)\times 3^{2} }{190+186-2} }[/tex] = 3
So, the test statistics = ~
= -2.908
The value of t-test statistics is -2.908.
Now, at a 0.05 level of significance, the t table gives a critical value of -1.645 at 374 degrees of freedom for the left-tailed test.
Since the value of our test statistics is less than the critical value of t as -2.908 < -1.645, so we have sufficient evidence to reject our null hypothesis as the test statistics will fall in the rejection region.
Therefore, we conclude that prenatal cocaine exposure is associated with lower scores of four-year-old children on the test of object assembly.
In the null hypothesis, a test always forecasts no effect, while the alternate theory states the research expectation impact, and calculation as follows:
Null and alternative hypothesis:Calculating the pooled estimator of [tex]\sigma^2[/tex], denoted by [tex]S^2_p[/tex], is defined by
[tex]\to \bold{S^2_p= \frac{(n_1 - 1) S^2_1+ (n_2 - 1)S^2_2}{n_1 + n_2 - 2}}[/tex]
Null hypothesis:
[tex]\to H_0 : \mu_1 - \mu_2 = \Delta_0\\[/tex]
Test statistic:
[tex]\to T_0=\frac{\bar{X_1}- \bar{X_2} -\Delta_0}{S_p \sqrt{\frac{1}{n_1}+\frac{1}{n_2}}} \\\\[/tex]
Alternative Hypothesis:
[tex]H_1 : \mu_1 -\mu_2 \neq \Delta_0\\\\ H_1 : \mu_1 -\mu_2 > \Delta_0\\\\H_1 : \mu_1 -\mu_2 < \Delta_0\\\\[/tex]
Rejection Criterion
[tex]t_0 > t_{\frac{\alpha}{2} , n_1+n_2 -2}\ \ \ or\ \ \ t_0 < - t_{\frac{\alpha}{2} , n_1+n_2 -2} \\\\t_o > t_{\alpha , n_1+n_2 -2} \\\\t_o > -t_{\alpha , n_1+n_2 -2}[/tex]
Given value:
[tex]\to S_p=9\\\\\to \Delta_0=0\\\\\to t_0=-\frac{0.9}{3(\sqrt{(\frac{1}{190}+\frac{1}{186})})}=-2.9\\\\\to t_{0.05,374}=1.645\\\\[/tex]
here
[tex]\to t_0 < -t_{0.05,374}[/tex]
hence rejecting the [tex]H_0[/tex]
Since there should be enough evidence that prenatal cocaine exposure is linked to inferior item assembly scores in 4-year-olds.
Find out more about the alternative hypothesis here:
brainly.com/question/18831983
