Answer:
C. 329
Step-by-step explanation:
So 28 is 70% of 40
so we know that 70% percent of students have phones
70% of 470
329
Thats how I solved it have a great day :)
A manufacturer claims that the calling range (in feet) of its 900-MHz cordless telephone is greater than that of its leading competitor. A sample of 19 phones from the manufacturer had a mean range of 1160 feet with a standard deviation of 32 feet. A sample of 11 similar phones from its competitor had a mean range of 1130 feet with a standard deviation of 30 feet.
Required:
Do the results support the manufacturer's claim?
Complete question is;
A manufacturer claims that the calling range (in feet) of its 900-MHz cordless telephone is greater than that of its leading competitor. A sample of 19 phones from the manufacturer had a mean range of 1160 feet with a standard deviation of 32 feet. A sample of 11 similar phones from its competitor had a mean range of 1130 feet with a standard deviation of 30 feet. Required:
Do the results support the manufacturer's claim?
Let μ1 be the true mean range of the manufacturer's cordless telephone and μ2 be the true mean range of the competitor's cordless telephone. Use a significance level of α = 0.01 for the test. Assume that the population variances are equal and that the two populations are normally distributed
Answer:
We will fail to reject the null hypothesis as there is no sufficient evidence to support the manufacturers claim.
Step-by-step explanation:
For the first sample, we have;
Mean; x'1 = 1160 ft
standard deviation; σ1 = 32 feet
Sample size; n1 = 19
For the second sample, we have;
Mean; x'2 = 1130 ft
Standard deviation; σ2 = 30 ft
Sample size; n2 = 11
The hypotheses are;
Null Hypothesis; H0; μ1 = μ2
Alternative hypothesis; Ha; μ1 > μ2
The test statistic formula for this is;
z = (x'1 - x'2)/√[(σ1)²/n1) + (σ2)²/n2)]
Plugging in the relevant values, we have;
z = (1160 - 1130)/√[(32)²/19) + (30)²/11)]
z = 2.58
From the z-table attached, we have a p-value = 0.99506
This p-value is more than the significance value of 0.01,thus,we will fail to reject the null hypothesis as there is no sufficient evidence to support the manufacturers claim.
Say we decided to expand our study and asked ten more urban homeowners what they pay each month for rent. Assume the sample deviation remains the same. What will happen to our samples standard error
Complete Question
The complete question is shown on the first uploaded image
Answer:
The correct option is C
Step-by-step explanation:
Generally the sample standard error is mathematically represented as
[tex]\sigma_{\= x } = \frac{\sigma }{ \sqrt{n} }[/tex]
Where [tex]\sigma[/tex] is the standard deviation and n is the sample size
Now looking at the formula we see that
[tex]\sigma_{\= x } \ \ \ \alpha \ \ \ \frac{1}{ \sqrt{n} }[/tex]
So at constant [tex]\sigma[/tex] if n increases [tex]\sigma_{\= x }[/tex] decreases
So from the question if ten more urban homeowners are asked the question the samples standard error decreases
Please solve this question by using the strategy Elimination Method or Solve By Substitution. This is the math equation: 1/2x+y=15 and -x-1/3y=-6
2nd Question: 5/6x+1/3y=0 and 1/2x-2/3y=3
First pair of equations :
[tex]\dfrac{1}{2}x+y=15\ ..(i)\\\\-x-\dfrac{1}{3}y=-6\ ..(ii)[/tex]
Multiply 2 to equation (i), we get
[tex]x+2y=30\ ..(iii)[/tex]
By Elimination Method, Add (i) and (ii) (term with x eliminate), we get
[tex]2y-\dfrac{1}{3}y=30-6\\\\\Rightarrow\ \dfrac{5}{3}y=24\\\\\Rightarrow\ y=\dfrac{24\times3}{5}=14.4[/tex]
put y= 14.4 in (iii), we get
[tex]x+2(14.4)=30\Rightarrow\ x=30-28.8=1.2[/tex]
hence, x=1.2 and y =14.4
Second pair of equations :
[tex]\dfrac{5}{6}x+\dfrac13y=0\ ..(i)\\\\ \dfrac12x-\dfrac{2}{3}y=3\ ..(ii)[/tex]
Multiply 2 to equation (i), we get
[tex]\dfrac{5}{3}x+\dfrac{2}{3}y=0\ ..(iii)[/tex]
Elimination Method, Add (i) and (ii) (term with y eliminate) , we get
[tex]\dfrac53x+\dfrac12x=3\Rightarrow\ \dfrac{10+3}{6}x=3\\\\\Rightarrow\ \dfrac{13}{6}x=3\\\\\Rightarrow\ x=\dfrac{18}{13}[/tex]
put [tex]x=\dfrac{18}{13}[/tex] in (i), we get
[tex]\dfrac{5}{6}(\dfrac{18}{13})+\dfrac{1}{3}y=0\\\\\Rightarrow\ \dfrac{15}{13}+\dfrac{1}{3}y=0\\\\\Rightarrow\ \dfrac{1}{3}y=-\dfrac{15}{13}\\\\\Rightarrow\ y=-\dfrac{45}{13}[/tex]
hence, [tex]x=\dfrac{18}{13}[/tex] and [tex]y=\dfrac{-45}{13}[/tex] .
1 - Dada a função f(x)= -Ix²-5x+4I, determine o valor de função para x = -1. * 1 ponto a) -10 b) 10 c) 9 d) -9 e) -8
Option a) -10
[tex] f(x)=-|x^2-5x+4|[/tex]
put $x=-1$
$f(-1)=-|(-1)^2-5(-1)+4|$
$\implies f(-1)=-|1+5+4|=-|10|=10$
Answer:
option a
Step-by-step explanation:
Option a) -10
put $x=-1$
$f(-1)=-|(-1)^2-5(-1)+4|$
$\implies f(-1)=-|1+5+4|=-|10|=10$
I need someone to answer this question for me correctly please?
Answer:
[tex]\boxed{x \leq -4}[/tex]
Step-by-step explanation:
Hey there!
Well to solve for x in,
16x - 7 ≤ -71
We need to single out x.
16x - 7 ≤ -71
+7 to both sides
16x ≤ -64
Divide both sides by 16
x ≤ -4
Hope this helps :)
Answer:
x ≤ -4
I hope this helps!
120 meals to 52 meals what is the percentage change?
Answer: The percentage change is 56.67%.
Step-by-step explanation:
From 120 meals to 52 meals, change in meals = ( 120- 52) meals
= 68 meals
The percentage change = [tex]\dfrac{\text{change in meals}}{\text{Original quantity of meals}}\times100[/tex]
[tex]=\dfrac{68}{120}\times100\\\\=56.67\%[/tex]
Hence, the percentage change is 56.67%.
Suppose a vine maple grows in height linearly. Four weeks after it is planted it stands 10.67 inches, and after seven weeks it is 15.67 inches tall. Write an equation that models the growth, in inches, of the vine maple as a function of time, in weeks. 1. What is the slope of the function? 2. How tall was the tree when it was first planted? 3. Write the function 4. How tall will the vine maple be after 16 weeks?
Answer:
Height (z)= 4+(5/3)(z)
Where z is the number of weeks
1). Slope = 4
2). Height= 5.67 inches
3).Height (z)= 4+(5/3)(z)
4).Height= 30.67 inches
Step-by-step explanation:
At week four
10.67= x+4y
Week 7
15.67= x+7y
Solving both equation simultaneously
3y= 5
Y= 5/3
15.67= x+7y
15.67= x+7(5/3)
15.67-35/3= x
15.67-11.67= x
4= x
The modeled equation is
Height (z)= 4+5/3(z)
Where z is the number of weeks
Slope of the function as compared to y= mx+c is 4
The first week of it's plantation
Height (z)= 4+5/3(z)
Height (1)= 4+5/3(1)
Height= 5.67 inches
After 16 weeks
Height (z)= 4+(5/3)(z)
Height (16)= 4+(5/3)(16)
Height= 30.67 inches
A major traffic problem in the Greater Cincinnati area involves traffic attempting to cross the Ohio River from Cincinnati to Kentucky using Interstate 75. Let us assume that the probability of no traffic delay in one period, given no traffic delay in the preceding period, is 0.9 and that the probability of finding a traffic delay in one period, given a delay in the preceding period, is 0.6. Traffic is classified as having either a delay or a no-delay state, and the period considered is 30 minutes.Required:a. Assume that you are a motorist entering the traffic system and receive a radio report of a traffic delay. What is the probability that for the next 60 minutes (two time periods) the system will be in the delay state?b. What is the probability that in the long run the traffic will not be in the delay state?c. An important assumption of the Markov process model presented here has been the constant or stationary transition probabilities as the system operates in the future. Do you believe this assumption should be questioned for this traffic problem? Explain.
Answer:
a) 0.36
b) 0.3
c) Yes
Step-by-step explanation:
Given:
Probability of no traffic delay in one period, given no traffic delay in the preceding period = P(No_Delay) = 0.9
Probability of finding a traffic delay in one period, given a delay in the preceding period = P(Delay) = 0.6
Period considered = 30 minutes
a)
Let A be the probability that for the next 60 minutes (two time periods) the system will be in the delay state:
As the Probability of finding a traffic delay in one period, given a delay in the preceding period is 0.6 and one period is considered as 30 minutes.
So probability that for the next two time periods i.e. 30*2 = 60 minutes, the system in Delay is
P(A) = P(Delay) * P(Delay) = 0.6 * 0.6 = 0.36
b)
Let B be the probability that in the long run the traffic will not be in the delay state.
This statement means that the traffic will not be in Delay state but be in No_Delay state in long run.
Let C be the probability of one period in Delay state given that preceding period in No-delay state :
P(C) = 1 - P(No_Delay)
= 1 - 0.9
P(C) = 0.1
Now using P(C) and P(Delay) we can compute P(B) as:
P(B) = 1 - (P(Delay) + P(C))
= 1 - ( 0.6 + 0.10 )
= 1 - 0.7
P(B) = 0.3
c)
Yes this assumption should be questioned for this traffic problem because it implies that traffic will be in Delay state for the 30 minutes and just after 30 minutes, it will be in No_Delay state. However, traffic does not work like this in general and it makes this scenario unrealistic. Markov process model can be improved if probabilities are modeled as a function of time instead of being presented as constant (for 30 mins).
helpppppppppppppppppppppppppppp give bralienst
Answer:
Brainliest! Hope I helped!
Step-by-step explanation:
you know its greater than 1cm and less than 2cm,
1 and 7hundreths cm is = 1.07 cm
thats not right because you know it is greater than that for sure!
so the only answer left is 1.7 cm
You answer is 1.7 cm
another way...
read the ruler and see the answer
Answer:
1.7 cm.
Step-by-step explanation:
The midpoint of 1 - 2 is 5 so count the lines after 5 and you get .7 to add to one cm.
Hope this helps, have a good day :)
Which equation represents a line with slope į and y-intercept -6?
2x +3y=-6
3x - 2y= 6
2x - 3y= 18
3x - 2y= 12
Answer:
Answer:y=-2/9+3
Step-by-step explanation:
If SSR is 2592 and SSE is 608, then A. the standard error would be large. B. the coefficient of determination is .23. C. the slope is likely to be insignificant. D. the coefficient of determination is .81.
Answer:
D. the coefficient of determination is .81.
Step-by-step explanation:
SST = SSE + SSR
where
SST is the summation of square total
SSE is the summation of squared error estimate = 608
SSR is the summation of square of residual = 2593
with these in mind we put the values into the formula
= 2592 + 608
=3200
Coefficient of determination = SSR/SST
= 2592/3200
= 0.81
Therefore option D is the correct answer to the question.
4. The general population (Population 2) has a mean of 30 and a standard deviation of 5, and the cutoff Z score for significance in a study involving one participant is 1.96. If the raw score obtained by the participant is 45, what decisions should be made about the null and research hypotheses?
Answer:
The null hypothesis is rejected and research hypotheses is supported
Step-by-step explanation:
From the question we are told that
The population mean is [tex]\mu = 30[/tex]
The standard deviation is [tex]\sigma = 5[/tex]
The sample size is n = 1
The cutoff Z score for significance is [tex]Z_{\alpha } = 1.96[/tex]
The mean score is [tex]\= x = 45[/tex]
Generally the test hypothesis is mathematically represented as
[tex]t = \frac{\= x - \mu }{ \frac{ \sigma }{\sqrt{n} } }[/tex]
=> [tex]t = \frac{45 - 30 }{ \frac{ 5}{\sqrt{1} } }[/tex]
=> [tex]t = 3[/tex]
From the obtained value we can see that [tex]t > Z_{\alpha }[/tex]
Hence the null hypothesis is rejected and research hypotheses is supported
The circumference of a redwood tree trunk is 16π ft, and it is 100 ft tall. What is the approximate volume of the redwood tree trunk? 2,560π ft3 640π ft3 25,600π ft3 6,400π ft3
Answer:
volume of redwood tree is 6400 π ft^3(option 4)
Step-by-step explanation:
concept =
volume of cylinder = πr^2l
where r is the radius and l is the length of cylinder
circumference of cylinder = 2πr
_____________________________________
shape of redwood tree can be taken as cylindrical
given
circumference of a redwood tree trunk is 16π ft
2πr = 16π
=> r = 16π/2π = 8
Thus, radius is 8 feet
Therefore volume of redwood tree = πr^2l = π8^2*100 = π*64*100
volume of redwood tree =6400 π ft^3
Answer:
6,400π ft3
Step-by-step explanation:
took test and got it right
Explain how to solve the inequality (x + 1)(x – 2) ∙ (x – 3) > 0. Explain in your own words, each step necessary to solve the inequality, making sure to follow the proper order of operations. Is this inequality accurate? Explain why or why not.
Answer:
[tex]x > -1[/tex] or
[tex]x > 2[/tex] or
[tex]x > 3[/tex]
Step-by-step explanation:
Given
[tex](x + 1)(x - 2) (x - 3) > 0[/tex]
Required
Solve; with steps
[tex](x + 1)(x - 2) (x - 3) > 0[/tex]
Start by splitting the inequality as follows
[tex]x + 1 > 0[/tex] or [tex]x - 2 > 0[/tex] or [tex]x - 3 > 0[/tex]
Solve the inequalities one after the other
Solving: [tex]x + 1 > 0[/tex]
Subtract 1 from both sides
[tex]x + 1 - 1 > 0 - 1[/tex]
[tex]x > -1[/tex]
Solving: [tex]x - 2 > 0[/tex]
Add 2 to both sides
[tex]x - 2 +2 > 0 +2[/tex]
[tex]x > 2[/tex]
Solving: [tex]x - 3 > 0[/tex]
Add 3 to both sides
[tex]x - 3 +3> 0+3[/tex]
[tex]x > 3[/tex]
Hence, the solution to the inequality is
[tex]x > -1[/tex] or
[tex]x > 2[/tex] or
[tex]x > 3[/tex]
Two tablespoons of peanut butter contain 190 calories. Two tablespoons of grape jelly contain 122 calories. Which contains more calories, two tablespoons of peanut butter or two tablespoons of grape jelly?
What is the perimeter of the triangle?
You spend $7.00 at the store. The sales tax is 6%. How much is your total bill?
Please explain how you got the answer if you can.
Answer:
7.42
Step-by-step explanation:
First determine the amount of tax
7 * 6%
7 *.06
.42
Add this to the original bill
7 + .42
7.42
The total cost is 7.42
URGENT! 15 PNTS
Points T, R, and P, define _____
A. plane B
B. line e
C. line segment PR⎯⎯⎯⎯⎯⎯⎯
D. plane M
Answer:
Since points T, R, and P are all present on plane B, the answer is A.
Points T, R, and P define plane B
We have given that,
A. plane B
B. line e
C. line segment PR⎯⎯⎯⎯⎯⎯⎯
D. plane M
We have to determine the Points T, R, and P, define
What is the plane?A plane is a two-dimensional doubly ruled surface spanned by two linearly independent vectors. The generalization of the plane to higher dimensions is called a hyperplane. The angle between two intersecting planes is known as the dihedral angle.
Since points T, R, and P are all present on plane B, the answer is A
Points T, R, and P define plane B.
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Solve the following system of equations: y + 5 = x
y= x2 – 3x – 5
Answer:
X=0,y=-5
x=4,y=-1
Step-by-step explanation:
Replace all occurrences of y with x^2-3x-5
(x^2-3x-5)+5=x
x^2-3x=x
X^2-4x=0
so :x=0,4
enter the value of x in the equation then find y
y=-5,-1
find the equation of the sides of an isosceles right angled triangle whose vertex is (-2,-3) and the base is on the line x=0
Answer:
AC:y=x-1 CB:y=-x-5 AB:x=0
Step-by-step explanation:
Consider the triangle. The base AB is on the line x=0, the vertex C is (-2,-3)
The side AC is equal to BC. The angle ACB is 90 degrees. If the base is on the line x=o, it is on the axis Y.Explore the distance from the point C to the AB
c(-2,-3), the distance to the axis Y is equal to the modul of the coordinate x (-2), it is 2. The coordinates of point projected by the point C to the axis Y is N(0,-3). The modul of the height is 2, the height of the isosceles triangle to the base is the bisectrix, so the angle BCA is 90/2=45degrees, CBA is 180-90-45=45 degrees too
the heigt CN is equal to side NB, NB=2
Suppose B is (0,y) (x=0 because the base is on this line)
THe modul of the vector NB is equal to sqrt ((0-0)^2+(y+3)^2)= 2
modul (y+3)= 2
y=-1 or y=-5
(0,-1), (0,-5) - two points, one of them (suppose B) is (0,-5) when A is (0,-1) (A is remote from the point N on the same distance with B, because AB is the median too)
Find CB and AC
Use the equation for AC
(x-0)/(-2-0)= (y+1)/(-3+1)
x/-2= (y+1)/-2
x=y+1
y=x-1
For CB
(x-0)/ (-2-0)= (y+5)/ (-3-(-5))
x/-2= (y+5)/2
-x=y+5
y=-x-5
A television camera at ground level is filming the lift-off of a space shuttle at a point 750 meters from the launch pad. Find the angle of elevation to the shuttle when the height of the shuttle is 300 meters.
Answer:
21.8°
Step-by-step explanation:
tan(θ) = opposite / adjacent
tan(θ) = 300 / 750
θ = arctan(300 / 750)
θ = 21.8°
Answer:
theta=21.8014
Step-by-step explanation:
We want to find theta
Since this is a right triangle, we can use trig functions
tan theta = opp /adj
tan theta = 300/750
Taking the inverse tan of each side
tan^-1(tan theta) = tan^-1(300/750)
theta=21.8014
I need help with this question.
Answer:
Complement = 15 Degrees
Supplement = 105 Degrees
Step-by-step explanation:
The complement of an angle refers to the measure that will make the angle 90 degrees. So, the complement of 75 would be 15, since 90 - 75 = 15.
The supplement of an angle refers to the measure that will make the angle 180 degrees. So, the supplement of 75 would be 105, since 180-75 = 105.
Cheers.
The function g is defined as follows for the domain given.
g(x) = 2x+1,
domain = (-5, -1, 2, 3)
Write the range of g using set notation. Then graph g
Answer:
g(x): 2(-5)+1= -10+1=-9
2(-1)+1= -2+1=-1
2(2)+1= 4+1=5
2(3)+1=6+1= 7
Hence, the range of [tex]g[/tex] using the set notation is [tex](-9,-1,5,7)[/tex].
What is the function?
Functions are often defined by a formula that describes a combination of arithmetic operations and previously defined functions; such a formula allows computing the value of the function from the value of any element of the domain.
Here given that,
The function g is defined as follows for the domain given.
[tex]g(x) = 2x+1,[/tex] and domain [tex]= (-5, -1, 2, 3)[/tex]
So,
[tex]x=-5\\2(-5)+1\\= -10+1\\=-9\\\\x=-1\\2(-1)+1\\= -2+1\\=-1\\\\x=2\\2(2)+1\\= 4+1\\=5\\\\x=3\\2(3)+1\\=6+1\\= 7[/tex]
Hence, the range of [tex]g[/tex] using the set notation is [tex](-9,-1,5,7)[/tex].
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ASAP
Which of the following factors determine a plane? A. line and a point on the line B. two lines C. a straight line D. a line and a point not on that line
Answer:
D. a line and a point not on that line
Step-by-step explanation:
That is how you determine a plane.
The factors which determine a plane are a line and a point not on that line.
What is plane ?
In geometry, a plane is a flat surface that extends into infinity.
In a three dimensional space, a plane can be defined by three points it contains, as long as those points are not on the same line.
Therefore, the factors which determine a plane are a line and a point not on that line.
Hence, option D is correct.
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Find 0.01 more than 9.154
Answer:
Hey!
Your answer is 9.164!!
Step-by-step explanation:
Adding 0.01 means just adding 1 to THE DIGIT IN THE HUNDRETH PLACE...2 SPACES RIGHT OF DECIMAL POINT!
5+1=6
SUB IN:
9.164
Identify the equivalent expressions of 4(2x + x-3) - 3x + 3 by substituting x = 2 and x = 3.
9x - 9
9x - 1
9x + X-9
9(x - 1)
4(3x - 3) + 3 - 3x
Answer:
9x -9
9(x - 1)
4(3x-3) - 3x + 3
Step-by-step explanation:
4(2x + x-3) - 3x + 3
Combine like terms
4(3x-3) - 3x + 3
Distribute
12x -12 -3x+3
Combine like terms
9x -9
Factor out 9
9(x-1)
Answer:
9
18
Step-by-step explanation:
x = 2:
4(4 + 2 - 3) - 6 + 3 = 12 - 6 + 3 = 9
x = 3:
4(6 + 3 - 3) - 9 + 3 = 24 - 9 + 3 = 18
Malek sets out for a hike at 8.00 am and returns at 17:15.
How long was Malek hiking for?
hours and
minutes
Answer:
9 hours and 15 mins
Step-by-step explanation:
17 - 8 (time calculation)
A student wrote the following equation and solution. Explain the error and correctly solve the equation: √p = 9/16 p = 3/4
Answer:
see below
Step-by-step explanation:
√p = 9/16
We need to square each side, not take the square root
(√p)^2 =( 9/16)^2
p = 81/256
Solve the following formula for a.
Answer:
B is correct .trust me
Step-by-step explanation:
Which cross-sectional shapes do you find the most surprising? Which shapes do you find the least surprising? Explain why.
Answer:
I was surprised that a plane parallel to the vertical axis creates a rectangular cross-section. I guess I was expecting to always see a circle or a circular shape in the cross-section, not purely straight edges as seen in a rectangle.
Step-by-step explanation:
edmentum answer
Answer:
The circles were the least surprising because the base of the cone is a circle. The curves that look like bent rods were the most surprising because I have not seen geometric figures like those before.
Step-by-step explanation: