Answer:
B.
Step-by-step explanation:
The function above the x-axis looks like a parabola, so it must have an x^2 term. It also has an open circle, so it must have a > symbol.
The function below the x-axis has a closed circle, so it must have a <= symbol. It is also a 3rd degree polynomial.
Answer: B.
You're at a clothing store that dyes your clothes while you wait. You get to pick from 444 pieces of clothing (shirt, pants, socks, or hat) and 333 colors (purple, blue, or orange). If you randomly pick the piece of clothing and the color, what is the probability that you'll end up with an orange hat?
Answer:
Probability of orange hat = 0.0833
Step-by-step explanation:
We have to find the probability of getting an orange hat while we randomly choose from 444 pieces of clothing and 333 colors.
So we have to get hat from the clothing and we have to get orange color from the colors. All shirts , pants , socks and hats are in equal numbers and are 111 each. Also purple, blue and orange are 111 each in number.
The probability of getting hats =
= 0.25
The probability of getting orange = = 0.333
Final probability = 0.25 0.333
= 0.0833
Answer: 1/12
Step-by-step explanation:
I just had khan academy
Find the equation, in standard form, of the line passing through the points
(2,-3) and (4,2).
Answer:
Standard form = y = mx + c
m = Δy/Δx
m = 5/2
y = 5/2 x + c
Sub in (4,2)
2 = 10 + c
c = -8
y = 5/2 x - 8
Step-by-step explanation:
Please answer this correctly without making mistakes
Answer:
2/7
Step-by-step explanation:
Joseph bought a cheese and cut it into 7 equal pieces, so the denominator is 7.
Saved 5 pieces for cooking.
Gave 2 pieces to Omar.
Hope this helps :) ❤❤❤
Answer:
Step-by-step explanation:
if he gives to Omar 2 pieces of 7
2/7 = 28.57% for Omar rest of is for himself
Find the difference of functions at x= - 3, (g - f)(-3), given f(x) and g(x): g(x) = x^2−15, and f(x) =2x
Answer:
0
Step-by-step explanation:
Solution:-
We are given two functions as follows:
[tex]f ( x ) = x^2 - 15\\\\g ( x ) = 2x[/tex]
We need to determine the composite function defined as ( g - f ) ( x ). To determine this function we need to make sure that both function exist for all real positive value of x.
The function f ( x ) is a quadratic function which has real values for all values of x. Similarly, function g ( x ) is a linear line that starts from the origin. Hence, both functions are defined over the domain ( -∞, ∞ )
We will perform arithmetic operation of subtracting function f ( x ) from g ( x ) as follows:
[tex][ g - f ] ( x ) = g ( x ) - f ( x )\\\\\\( g - f ) ( x ) = x^2 - 15 - 2x\\\\[/tex]
Now evaluate the above determined function at x = -3 as follows:
[tex]( g - f ) ( -3 ) = ( -3 )^2 - 2 ( -3 ) - 15\\\\( g - f ) ( -3 ) = 9 + 6 - 15\\\\( g - f ) ( -3 ) = 0[/tex]
A rectangle's length and width are in a ratio of 10:1. The perimeter is 66 feet. What are the length and width?
hii
Step-by-step explanation:
length-10x
width-x
perimeter-2(l+b)
66=2(10x+x)
66-2=10x+x
64=11x
x=11/64
lenght-11
width-64
Solve the quadratic equation 4x2 – 2x = 9 using the quadratic formula
Answer:
x= 1 + or - sr37/4 got it from a sitr
Here you go.
I really hope I helped. Good luck.
helppppppppppppp pleaseeeeeeeeeeeeee
Answer:
work is shown and pictured
which numbers are the extremes of the proption shown below. 3/4 = 6/8
Answer:
3 and 8
Step-by-step explanation:
Given the proportion:
[tex] \frac{3}{4} = \frac{6}{8}[/tex]
Required:
Find the extreme values.
When given an equation like the one we have here, there is always a very easy way to find the extreme value.
First make rewrite to a ratio form:
Example:
a:b = c:d
Just know that extreme values are the values on the outside of the ratio(a & d)
Therefore,
3:4 = 6:8
When it is written this way extreme values are 3 & 8
Extreme values = 3 and 8
What percentage of babies born in the United States are classified as having a low birthweight (<2500g)? explain how you got your answer?
Answer:
2.28% of babies born in the United States having a low birth weight.
Step-by-step explanation:
The complete question is: In the United States, birth weights of newborn babies are approximately normally distributed with a mean of μ = 3,500 g and a standard deviation of σ = 500 g. What percent of babies born in the United States are classified as having a low birth weight (< 2,500 g)? Explain how you got your answer.
We are given that in the United States, birth weights of newborn babies are approximately normally distributed with a mean of μ = 3,500 g and a standard deviation of σ = 500 g.
Let X = birth weights of newborn babies
The z-score probability distribution for the normal distribution is given by;
Z = [tex]\frac{X-\mu}{\sigma}[/tex] ~ N(0,1)
where, [tex]\mu[/tex] = population mean = 3,500 g
[tex]\sigma[/tex] = standard deviation = 500 g
So, X ~ N([tex]\mu=3500, \sigma^{2} = 500[/tex])
Now, the percent of babies born in the United States having a low birth weight is given by = P(X < 2500 mg)
P(X < 2500 mg) = P( [tex]\frac{X-\mu}{\sigma}[/tex] < [tex]\frac{2500-3500}{500}[/tex] ) = P(Z < -2) = 1 - P(Z [tex]\leq[/tex] 2)
= 1 - 0.97725 = 0.02275 or 2.28%
The above probability is calculated by looking at the value of x = 2 in the z table which has an area of 0.97725.
Answer:
The z-score for 2,500 is -2. According to the empirical rule, 95% of babies have a birth weight of between 2,500 g and 4,500 g. 5% of babies have a birth weight of less than 2,500 g or greater than 4,500 g. Normal distributions are symmetric, so 2.5% of babies weigh less than 2,500 g.
Step-by-step explanation:
did the assignment on edge:)
1/3 x =6 What would like match this answer
Answer:
x=18
Step-by-step explanation:
Answer:
x = 18
Step-by-step explanation:
Since 1/3x = 6,
x = 6 x 3
Thus, x = 18
Find the measure of angle angle AGE in the figure below. Enter only the number.
Help please!
Answer:
AGE = 129 degrees
Step-by-step explanation:
Two angles whose sum is 180° are called supplementary angles. The measure of ∠AGE in the given figure is 129°.
What are supplementary angles?Two angles whose sum is 180° are called supplementary angles. If a straight line is intersected by a line, then there are two angles form on each of the sides of the considered straight line. Those two-two angles are two pairs of supplementary angles. That means, that if supplementary angles are aligned adjacent to each other, their exterior sides will make a straight line.
In the given figure, line segment CE is a straight line. Therefore, the sum of the angles formed on the same side of the line will be a linear pair.
Thus, the measure of the angles can be rewritten as,
∠AGC + ∠AGE = 180°
51° + ∠AGE = 180°
∠AGE = 180° - 51°
∠AGE = 129°
Learn more about Supplementary Angles:
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what is the vertex of f(x)=-3(x+2)^2+4
Answer:
vertex(-2,4)
Step-by-step explanation:
f(x)=-3(x+2)^2+4
f(x)=-3(x²+4x+4)+4
f(x)=-3x²-12x-12+4
= -3x²-12x-8
v(h,k)
h=-b/2a=-(12/-6)==2
substitute for x=-2
k=-3(2)²-12(-2)-8=-12+24-8=4
2.CommerceThe weight distribution of parcels sent in a certain manner is normal with meanvalue 12 pounds and standard deviation 3.5 pounds. The parcel service wishes to establish aweight valuecbeyond which there will be a surcharge. What value ofcis such that 99% ofall parcels are under the surcharge weight
Answer:
the value of c is 20.155 such that 99% of all parcels are under the surcharge weight.
Step-by-step explanation:
Given that :
The mean value [tex]\mu[/tex] = 12
The standard deviation [tex]\sigma[/tex] = 3.5
Let Consider Q to be the weight of the parcel that is normally distributed .
Then;
Q [tex]\sim[/tex] Norm(12,3.5)
The objective is to determine thewight value of c under which there is a surcharge
Also, let's not that 99% of all the parcels are below the surcharge
However ;
From the Percentiles table of Standard Normal Distribution;
At 99th percentile; the value for Z = 2.33
The formula for the Z-score is:
[tex]Z = \dfrac{X- \mu}{\sigma}[/tex]
[tex]2.33 = \dfrac{X - 12}{3.5}[/tex]
2.33 × 3.5 = X - 12
8.155 = X - 12
- X = - 12 - 8.155
- X = -20.155
X = 20.155
the weight value of c under which there is a surcharge = X + 1 (0) since all the pounds are below the surcharge
c = 20.155 + 1(0)
c = 20.155
Thus ; the value of c is 20.155 such that 99% of all parcels are under the surcharge weight.
The graph of a linear equation g(x)=-1/3x +2 can be obtained from the graph f(x)=1/3x by using infinite sets of elementary translation (i.e reflection and shifting). List out five of those sets
Answer:
{Rx, T(-6, 4)}{Rx, T(-3, 3)}{Rx, T(0, 2)}{Rx, T(3, 1)}{Rx, T(9, -1)}Step-by-step explanation:
We assume you are not interested in five infinite sets of translations. Rather, we assume you want to pick 5 translations from the infinite set of possibilities.
The attached graph shows f(x), g(x), and 5 lines (dashed or dotted) that represent possible reflections and shifts of the function f(x).
The function f1 represents a reflection of f(x) about the x-axis, followed by a left-shift of 6 units. To make it match g(x), we need to shift it upward 4 units. Then the set if translations is ...
g(x) = f(x) ... {reflected over the x-axis, shifted left 6, shifted up 4}
Along the same lines, other possibilities are ...
g(x) = f(x) ... {reflected over the x-axis, shifted left 3, shifted up 3}
g(x) = f(x) ... {reflected over the x-axis, shifted left 0, shifted up 2}
g(x) = f(x) ... {reflected over the x-axis, shifted right 3, shifted up 1}
g(x) = f(x) ... {reflected over the x-axis, shifted right 9, shifted down 1}
___
Additional comment
All of the transformations listed above use reflection in the x-axis. Reflection could use the y-axis, as well. Reflection of the basic function f(x) in the y-axis will have the identical effect as reflection in the x-axis. The listed translations would apply unchanged.
A sector with a central angle measure of 200 degrees has a radius of 9 cm. What is the area of the sector?
Answer:
[tex]\boxed{Area\ of\ sector = 141.4\ cm^2}[/tex]
Step-by-step explanation:
Radius = r = 9 cm
Angle = θ = 200° = 3.5 radians
Now,
[tex]Area \ of \ sector = \frac{1}{2} r^2 \theta[/tex]
Area = 1/2 (9)²(3.5)
Area = 1/2 (81)(3.5)
Area = 282.7 / 2
Area of sector = 141.4 cm²
Answer:
45 pi cm^2 or 141.3 cm^2
Step-by-step explanation:
First find the area of the circle
A = pi r^2
A = pi (9)^2
A = 81 pi
A circle has 360 degrees
The shaded part has 200
The fraction that is shaded is
200/360 =5/9
Multiply by the total area
5/9 * 81 pi
45 pi
Using 3.14 for pi
141.3
45 pi cm^2 or 141.3 cm^2
What is the value of 3X to the 2nd power
Answer:
9 x^2
Step-by-step explanation:
( 3x) ^2
We are multiplying 3x * 3x
9 x^2
whats the steps when solving 40-:8+3^(2)+(15-7)*2
Answer:
Step-by-step explanation:
Assuming the colon between 40 and 8 is a mistype...
PEMDAS(Parenthesis, Exponents, Multiplication + Division, Addition + Subtraction)
[tex]40-8+3^2+(15-7)*2\\\\Parenthesis\\\\40-8+3^2+8*2\\\\Exponents\\\\40-8+9+8*2\\\\Multiplication\\\\40-8+9+16\\\\Subtraction\\\\32+9+16\\\\Addition\\\\41+16\\\\Addition\\\\57[/tex]
Hope it helps <3
━━━━━━━☆☆━━━━━━━
▹ Answer
57
▹ Step-by-Step Explanation
You need to follow PEMDAS:
Parentheses
Exponents
Multiplication
Division
Addition
Subtraction
40 - 8 + 3² + (15 - 7)* 2
40 - 8 + 9 + (15 - 7) * 2
40 - 8 + 9 + 8 * 2
40 - 8 + 9 + 16
= 57
Hope this helps!
CloutAnswers ❁
Brainliest is greatly appreciated!
━━━━━━━☆☆━━━━━━━
The slope intercept form of a line is
y=mx+b
The slope is represented by____
The y-intercept is represented by____
Answer:y=Mx+b
Step-by-step explanation:
Alex : Hey Bob, I think this coin is biased; I flipped it a few times and it always lends Tail. I think p, the probability of landing Head, must be less than 5%. Can you take a look?
Bob: Seriously? I bet it's fair, that is I think p = 1/2. Let me flip it three times and count the number of Heads. If the number of Heads is smaller than some threshold t, then I will buy you dinner. Otherwise, you will buy me dinner.
Alex: Wow Bob, okay! I will go ahead and reserve a fancy restaurant.
Bob: One last thing, though, just to make things fair: pick any t you want, but let's keep the proba- bility that I buy you dinner even if I'm right (that is, even if the truth is p= 1/2) below 10% please.
Alex: Go away, Bob! Stop wasting my time!
Question: why did Alex get mad?
Answer:
See below
Step-by-step explanation:
Alex finally understands how Bob was trying to trick him into winning the bet because of how he puts in the condition for probability being less than 10%. Whichever way the outcome of the coin toss turns out to be, it will be in Bob's favor and Alex will lose the bet. If the coin is flipped 3 times, the probability of having heads exactly twice is [tex]\frac{4}{9}[/tex]
Use Stokes' Theorem to evaluate S curl F · dS. F(x, y, z) = zeyi + x cos(y)j + xz sin(y)k, S is the hemisphere x2 + y2 + z2 = 16, y ≥ 0, oriented in the direction of the positive y-axis.
Stokes' theorem equates the surface integral of the curl of F to the line integral of F along the boundary of the hemisphere. The boundary itself is a circle C (the intersection of the hemisphere with the plane y = 0) with equation
[tex]x^2+z^2=16[/tex]
Parameterize this circle by
[tex]\mathbf r(t)=4\cos t\,\mathbf i+4\sin t\,\mathbf k[/tex]
with [tex]0\le t\le2\pi[/tex].
The surface is oriented such that its normal vector points in the positive y direction, which corresponds to the curve having counterclockwise orientation. The parameterization we're using here already takes this into account.
Now compute the line integral of F along C :
[tex]\displaystyle\iint_S\mathrm{curl}\mathbf F(x,y,z)\cdot\mathrm d\mathbf S=\int_C\mathbf F(x,y,z)\cdot\mathrm d\mathbf r[/tex]
[tex]=\displaystyle\int_0^{2\pi}\mathbf F(4\cos t,0,4\sin t)\cdot\frac{\mathrm d\mathbf r}{\mathrm dt}\,\mathrm dt[/tex]
[tex]=\displaystyle\int_0^{2\pi}(4\sin t\,\mathbf i+4\cos t\,\mathbf j)\cdot(-4\sin t\,\mathbf i+4\cos t\,\mathbf k)\,\mathrm dt[/tex]
[tex]=\displaystyle\int_0^{2\pi}-16\sin^2t\,\mathrm dt[/tex]
[tex]=-8\displaystyle\int_0^{2\pi}(1-\cos(2t))\,\mathrm dt=\boxed{-16\pi}[/tex]
Line integral of F along C is,
[tex]\rm \int \int_S curl F(x,y,z) dS = -16\pi[/tex]
Step-by-step explanation:
Given :
Hemisphere - [tex]x^2 +y^2+z^2=16[/tex]
Calculation :
Accordind to Stoke's theorem the surface integral of the curl of F to the line integral of F along the boundary of the hemisphere. The boundary itself is a circle C (the intersection of the hemisphere with the plane y = 0) with equation
[tex]x^2+z^2=16[/tex]
then parameterize the circle,
[tex]\rm r(t) = 4 cos(t) \;\hat{i} + 4 sin(t)\;(\hat{k})[/tex]
with , [tex]0\leq t\leq 2\pi[/tex]
Line integral of F along C is,
[tex]\rm \int \int_S curl F(x,y,z) dS = \int_{C}^{} F(x,y,z) \;dr[/tex]
[tex]= \int_{0}^{2\pi} F(4cos(t),0,4sin(t)) \;\dfrac{dr}{dt}.dt[/tex]
[tex]= \int_{0}^{2\pi}(4sin(t)i+4cos(t) j).(-4sin(t)i+4cos(t)k) \;dt[/tex]
[tex]= \int_{0}^{2\pi} -16sin^2tdt[/tex]
[tex]=-8 \int_{0}^{2\pi} (1-cos(2t))dt[/tex]
[tex]= -16\pi[/tex]
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Find the value of x in the isosceles triangle shown below.
Answer:
x=10.
Step-by-step explanation:
Suppose that MNO is isosceles with base NM. Suppose also that =m∠N+4x7° and =m∠M+2x29°. Find the degree measure of each angle in the triangle.
Answer:
m∠N = 51°
m∠M = 31°
m∠O = 98°
Step-by-step explanation:
It is given that ΔMNO is an isosceles triangle with base NM.
m∠N = (4x + 7)° and m∠M = (2x + 29)°
By the property of an isosceles triangle,
Two legs of an isosceles triangle are equal in measure.
ON ≅ OM
And angles opposite to these equal sides measure the same.
m∠N = m∠M
(4x + 7) = (2x + 29)
4x - 2x = 29 - 7
2x = 22
x = 11
m∠N = (4x + 7)° = 51°
m∠M = (2x + 9)° = 31°
m∠O = 180° - (m∠N + m∠M)
= 180° - (51° + 31°)
= 180° - 82°
= 98°
For the following telescoping series, find a formula for the nth term of the sequence of partial sums {Sn}. Then evaluate Lim Sn to obtain the value of the series or state that the series diverges.
n→[infinity]
[infinity]
Σ (4/√k+5 ) - 4/ √ k+6)
k=1
Looks like the series is
[tex]\displaystyle\sum_{k=1}^\infty\left(\frac4{\sqrt{k+5}}-\frac4{\sqrt{k+6}}\right)[/tex]
This series has n-th partial sum
[tex]S_n=\displaystyle\sum_{k=1}^n\bullet[/tex]
(where [tex]\bullet[/tex] is used as a placeholder for the summand)
[tex]S_n=\displaystyle\left(\frac4{\sqrt6}-\frac4{\sqrt7}\right)+\left(\frac4{\sqrt7}-\frac4{\sqrt8}\right)+\cdots+\left(\frac4{\sqrt{n+4}}-\frac4{\sqrt{n+5}}\right)+\left(\frac4{\sqrt{n+5}}-\frac4{\sqrt{n+6}}\right)[/tex]
In each grouped term, the last term is annihilated by the first term of the next group; that is, for instance,
[tex]\displaystyle\left(\frac4{\sqrt6}-\frac4{\sqrt7}\right)+\left(\frac4{\sqrt7}-\frac4{\sqrt8}\right)=\frac4{\sqrt6}-\frac4{\sqrt8}[/tex]
Ultimately, all the middle terms will vanish and we're left with
[tex]S_n=\dfrac4{\sqrt6}-\dfrac4{\sqrt{n+6}}[/tex]
As [tex]n\to\infty[/tex], the last term converges to 0 and we're left with
[tex]\displaystyle\sum_{k=1}^\infty\bullet=\lim_{n\to\infty}S_n=\frac4{\sqrt6}=\boxed{2\sqrt{\dfrac23}}[/tex]
Need help with this, I don’t need an explanation.
the answer is x=-2
and y=12
Look at the parallelogram ABCD shown below. The table below shows the steps to prove that if the quadrilateral ABCD is a parallelogram, then its opposite sides are congruent. Statement Reasons 1 . AB is parallel to DC and AD is parallel to BC - definition of parallelogram 2 . angle 1 = angle 2, angle 3 = angle 4 - if two parallel lines are cut by a transversal then the corresponding angles are congruent 3 . BD = BD - Reflexive Property 4 . triangles ADB and CBD are congruent - if two sides and the included angle of a triangle are congruent to the corresponding sides and angle of another triangle , then the triangles are congruent by SAS postulate 5 . AB = DC, AD = BC - corresponding parts of congruent triangles are congruent Which statement is true about the table? 1. It is not correct because it provides incorrect sequence of statement 2 and statement 4. 2. It is not correct because it does not provide correct reasons for statement 2 and statement 4. 3. It is accurate because it provides the correct sequence of statements. 4. It is accurate because it provides the correct reasons for the statements.
Answer:
Can you add the image so i can anwser?
Step-by-step explanation:
a study of the annual population of toads in a county park shows the population, S(t), can be represented by the function S(t) = 152(1.045)^t, where the t represents the number of years since the study started. based on the function, what is the growth rate?
Answer: 0.045 is the growth rate.
Step-by-step explanation:
A generic exponential growth function can be written as:
f(t) = A*(1 + r)^t
where A is the initial amount.
t is the unit of time.
r is the rate of growth.
For example if we have an increase of 10% per year, with an initial population of 100 we have that:
A = 100, r = 10%/100% = 0.10, t = number of years.
the equation will be:
f(t) = 100*(1 + 0.10)^t
Now, in this case the equation is:
S(t) = 152*(1.045)^t
We can write this as:
S(t) = 152*(1 + 0.045)^t
Then 152 is the initial amount and 0.045 is the growth rate.
The circumference of the base of a cylinder is 24π mm. A similar cylinder has a base with circumference of 60π mm. The lateral area of the larger cylinder is 210π mm2. What is the lateral area of the smaller cylinder? 17.1π mm2 33.6π mm2 60π mm2 84π mm2
Answer:
84π mm^2
Step-by-step explanation:
formula for circumference is 2πr where r is the radius of circle
Given,The circumference of the base of a cylinder is 24π mm
Thus,
2πr= 24π mm
=> r = 24π mm/2π = 12 mm
________________________________________
A similar cylinder has a base with circumference of 60π mm.
radius for this cylinder will be
2πr= 60π mm
r = 60π mm/2π = 30mm
______________________________________________
Given
The lateral area of the larger cylinder is 210π mm2
lateral area of cylinder is given by 2πrl
where l is the length of cylinder
thus,
r for larger cylinder = 30mm
2π*30*l = 210π mm^2
=> l = 210π mm^2/2π*30 = 3.5 mm
___________________________________________
the lateral area of the smaller cylinder
r = 12 mm
l = 3.5 mm as both larger and smaller cylinder are same
2πrl = 2π*12*3.5 mm^2 = 84π mm^2 answer
Answer:
33.6pi mm2 is the correct answer
edge 2021
Step-by-step explanation:
The circumference of the base of a cylinder is 24π mm. A similar cylinder has a base with circumference of 60π mm. The lateral area of the larger cylinder is 210π mm2.
What is the lateral area of the smaller cylinder?
17.1π mm2
33.6π mm2
60π mm2
84π mm2
13. A hole is drilled in a block of wood as shown in the sketch. The hole is 3/4 of
the total depth of the wood. The total depth of the block of wood is 13/16 in.
How deep is the hole?
Hole
The depth of hole is 0.609 inches.
Given, the total depth of the block of wood is [tex]\frac{13}{16}[/tex] inches.
Since the hole is [tex]\frac{3}{4}[/tex] of the total depth, so the depth of the hole will be,
[tex]D=\frac{3}{4} \times\frac{13}{16}[/tex]
Or, [tex]D=\frac{39}{64}[/tex]
[tex]D=0.609375 \ in[/tex]
Hence the depth of hole is 0.609 inches.
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50 + 100n where n = 2
Hypothesis Testing
Problem 1. Adults saving for retirement
In a recent survey conducted by Pew Research, it was found that 156 of 295 adult Americans without a high school diploma were worried about having enough saved for retirement. Does
the sample evidence suggest that a majority of adult Americans without a high school diploma are worried about having enough saved for retirement? Use a 0.05 level of significance
1. State the null and alternative hypothesis.
2. What type of hypothesis test is to be used?
3. What distribution should be used and why?
4. Is this a right, left, or two-tailed test?
5. Compute the test statistic.
6. Compute the p-value.
7. Do you reject or not reject the null hypothesis? Explain why.
8. What do you conclude?
Problem 2: Google Stock
Google became a publicly traded company in August 2004. Initially, the stock traded over 10 million shares each day! Since the initial offering, the volume of stock traded daily has
decreased substantially. In 2010, the mean daily volume in Google stock was 5.44 million shares, according to Yahoo!Enance. A random sample of 35 trading days in 2014 resulted in a
sample mean of 3.28 million shares with a standard deviation of 1.68 million shares. Does the evidence suggest that the volume of Google stock has changed since 2007? Use a 0.05 level of
significance
1. State the null and alternative hypothesis.
2. What type of hypothesis test is to be used?
3. What distribution should be used and why?
4. Is this a right, left, or two-tailed test?
5. Compute the test statistic.
6. Compute the p-value.
7. Do you reject or not reject the null hypothesis? Explain why
8. What do you conclude?
Answer:
Problem 1: We conclude that less than or equal to 50% of adult Americans without a high school diploma are worried about having enough saved for retirement.
Problem 2: We conclude that the volume of Google stock has changed.
Step-by-step explanation:
Problem 1:
We are given that in a recent survey conducted by Pew Research, it was found that 156 of 295 adult Americans without a high school diploma were worried about having enough saved for retirement.
Let p = proportion of adult Americans without a high school diploma who are worried about having enough saved for retirement
So, Null Hypothesis, [tex]H_0[/tex] : p [tex]\leq[/tex] 50% {means that less than or equal to 50% of adult Americans without a high school diploma are worried about having enough saved for retirement}
Alternate Hypothesis, [tex]H_A[/tex] : p > 50% {means that a majority of adult Americans without a high school diploma are worried about having enough saved for retirement}
This is a right-tailed test.
The test statistics that would be used here is One-sample z-test for proportions;
T.S. = [tex]\frac{\hat p-p}{\sqrt{\frac{p(1-p)}{n} } }[/tex] ~ N(0,1)
where, [tex]\hat p[/tex] = sample proportion of adult Americans who were worried about having enough saved for retirement = [tex]\frac{156}{295}[/tex] = 0.53
n = sample of adult Americans = 295
So, the test statistics = [tex]\frac{0.53-0.50}{\sqrt{\frac{0.50(1-0.50)}{295} } }[/tex]
= 1.03
The value of z-test statistics is 1.03.
Also, the P-value of the test statistics is given by;
P-value = P(Z > 1.03) = 1 - P(Z [tex]\leq[/tex] 1.03)
= 1 - 0.8485 = 0.1515
Now, at a 0.05 level of significance, the z table gives a critical value of 1.645 for the right-tailed test.
Since the value of our test statistics is less than the critical value of z as 1.03 < 1.645, so we insufficient evidence to reject our null hypothesis as it will not fall in the rejection region.
Therefore, we conclude that less than or equal to 50% of adult Americans without a high school diploma are worried about having enough saved for retirement.
Problem 2:
We are given that a random sample of 35 trading days in 2014 resulted in a sample mean of 3.28 million shares with a standard deviation of 1.68 million shares.
Let [tex]\mu[/tex] = mean daily volume in Google stock
So, Null Hypothesis, [tex]H_0[/tex] : [tex]\mu[/tex] = 5.44 million shares {means that the volume of Google stock has not changed}
Alternate Hypothesis, [tex]H_A[/tex] : [tex]\mu[/tex] [tex]\neq[/tex] 5.44 million shares {means that the volume of Google stock has changed}
This is a two-tailed test.
The test statistics that would be used here is One-sample t-test statistics because we don't know about the population standard deviation;
T.S. = [tex]\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }[/tex] ~ [tex]t_n_-_1[/tex]
where, [tex]\bar X[/tex] = sample mean volume in Google stock = 3.28 million shares
s = sample standard deviation = 1.68 million shares
n = sample of trading days = 35
So, the test statistics = [tex]\frac{3.28-5.44}{\frac{1.68}{\sqrt{35} } }[/tex] ~ [tex]t_3_4[/tex]
= -7.606
The value of t-test statistics is -7.606.
Also, the P-value of the test statistics is given by;
P-value = P([tex]t_3_4[/tex] < -7.606) = Less than 0.05%
Now, at a 0.05 level of significance, the t table gives a critical value of -2.032 and 2.032 at 34 degrees of freedom for the two-tailed test.
Since the value of our test statistics doesn't lie within the range of critical values of t, so we sufficient evidence to reject our null hypothesis as it will fall in the rejection region.
Therefore, we conclude that the volume of Google stock has changed.