Answer:
a) The 95% confidence interval for the mean mpg, for the certain model of car is (23.3, 30.1). This means that we are 95% sure that the true mean mpg of the model of the car is between 23.3 mpg and 30.1 mpg.
b) Increasing the confidence level, the value of T would increase, thus increasing the margin of error and making the interval wider.
c) 37 cars would have to be sampled.
Step-by-step explanation:
Question a:
We have the sample standard deviation, and thus, the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 15 - 1 = 14
95% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 14 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.95}{2} = 0.975[/tex]. So we have T = 2.1448
The margin of error is:
[tex]M = T\frac{s}{\sqrt{n}} = 2.1448\frac{6.2}{\sqrt{15}} = 3.4[/tex]
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 26.7 - 3.4 = 23.3 mpg.
The upper end of the interval is the sample mean added to M. So it is 26.7 + 3.4 = 30.1 mpg.
The 95% confidence interval for the mean mpg, for the certain model of car is (23.3, 30.1). This means that we are 95% sure that the true mean mpg of the model of the car is between 23.3 mpg and 30.1 mpg.
b. What would happen to the interval if you increased the confidence level from 95% to 99%? Explain
Increasing the confidence level, the value of T would increase, thus increasing the margin of error and making the interval wider.
c. The lead engineer is not happy with the interval you constructed and would like to keep the width of the whole interval to be less than 4 mpg wide. How many cars would you have to sample to create the interval the engineer is requesting?
Width is twice the margin of error, so a margin of error of 2 would be need. To solve this, we have to consider the population standard deviation as [tex]\sigma = 6.2[/tex], and then use the z-distribution.
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 - 0.95}{2} = 0.025[/tex]
Now, we have to find z in the Z-table as such z has a p-value of [tex]1 - \alpha[/tex].
That is z with a pvalue of [tex]1 - 0.025 = 0.975[/tex], so Z = 1.96.
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.
How many cars would you have to sample to create the interval the engineer is requesting?
This is n for which M = 2. So
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
[tex]2 = 1.96\frac{6.2}{\sqrt{n}}[/tex]
[tex]2\sqrt{n} = 1.96*6.2[/tex]
[tex]\sqrt{n} = \frac{1.96*6.2}{2}[/tex]
[tex](\sqrt{n})^2 = (\frac{1.96*6.2}{2})^2[/tex]
[tex]n = 36.9[/tex]
Rounding up:
37 cars would have to be sampled.
A runner can run 2 miles in 14 minutes. At this rate, how many miles can he run in 70 minutes?
Answer:
The answer is that the runner can run 10 miles in 70 minutes.
Step-by-step explanation:
To solve for the number of miles that the runner can run in 70 minutes, start by setting up the information given from the problem in the form of a proportion.
A proportion is an equation which defines that the two given ratios are equivalent to each other. In other words, the proportion states the equality of the two fractions or the ratios. In a proportion, if two sets of given numbers are increasing or decreasing in the same ratio, then the ratios are said to be directly proportional to each other.
The proportion for this problem will look like [tex]\frac{2 miles}{14 minutes}=\frac{x}{70 minutes}[/tex]. (x) will be used as the variable for the number of miles that the runner can run in 70 minutes.
To solve the proportion, start by cross multiplying to form an equation, and the equation will look like [tex](14)(x)=(2)(70)[/tex]. Next, simplify the equation, which will look like [tex](14)(x)=140[/tex]. Then, solve the equation by dividing both sides of the equation by 14, and it will look like [tex]x=10[/tex]. The final answer is that the runner can run 10 miles in 70 minutes.
pls help Describe how to find the product of the two terms 3x^2y^5 and 4x^3y^7
Answer:
12 x^5y^12
Step-by-step explanation:
3x^2y^5 * 4x^3y^7
Multiply the constants
3*4 = 12
Multiply the x terms
x^2 * x^3
We know a^b* a^c = a^(b+c)
x^(2+3) = x^5
Multiply the y terms
y^6 * y^7 = y&(5+7) = y^12
Put them back together
12 x^5y^12
Find the value of k if y-' is a factor of y³ + 4y² + ky - 6
Answer:
1
step by step explanation
hope this helps :)
The LARGEST angle has a measure of ______degrees
Answer:
90 i think
Step-by-step explanation:
Three friends go grocery shopping together, and each buys the same kind of
strawberries. Akio buys 2 pounds (lb) and pays $3,50. Gordon buys 3 pounds
and pays $5.25. Maria buys 4 pounds and pays $7.00,
Identify the graph and unit price that represent the strawberry costs.
Unit Price
A. $1.75
1lb
b. $3.00
1lb
the bottom two are the same but with more space between the lines and they go up to 24
c $3.00
1lb
d. $1.75
1lb
9514 1404 393
Answer:
A.
Step-by-step explanation:
If you can find the given points (pounds, dollars) = (2, 3.50), (3, 5.25), and (4, 7.00) on the graph, then it is an appropriate graph. If the graph label matches the value it shows for 1 pound, then that graph and label are the one you want.
Graph A meets these requirements. It shows the cost of 1 lb to be $1.75, as the label says.
why is (3, -5) not a solution to -x+4=-15 and -2x-3y=-8
Step-by-step explanation:
-x+4y= -15
-2x-3y=-8
the intersection point isn't (3,-5)
it's approximately (-1.1818 ,3.45455 )
Answer:
see below
Step-by-step explanation:
Check the solution in both equation
-x+4 = -15
-3 +4 = -15
1 does not equal -15 so it is not a solution
-2x-3y = -8
-2(3)+-3(-5) = -8
-6 +15 = -8
9 = -8
It is not a solution to either equation
HELP NEEDED PLEASE!!!!
Answer:
A
Step-by-step explanation:
The period is stretched by 30 and divided by pi, meaning that the wheel rotates does a full rotation every 60 seconds. But the most important part is vertical stretch of 47 and shift up of 52. At the peak it would be 99 since the peak is 47 with the stretch but add 52 from the shift and it would be 99.
A chef is going to use a mixture two different brands of Italian dressing the first spring and days 5% vinegar the second brain contains 15% vinegar the sheriff wants to make 390$ ml addressing that is 9% vinegar how much of each brand should she use
I guess the chef is making the mixture for the sheriff... Let x be the amount of dressing with 5% vinegar that is required, and y the amount of 15% vinegar dressing (both amounts in mL).
The sheriff wants 390 mL of the mixed dressing, so that
x + y = 390
x mL of the 5% dressing contains 0.05x mL of vinegar, while y mL of the 15% dressing contains 0.15y mL of vinegar. The resulting mixture should have a concentration of 9% vinegar, so that it contains 0.09 (390 mL) = 35.1 mL of vinegar. This means
0.05x + 0.15y = 35.1
Solve for x and y :
y = 390 - x
0.05x + 0.15 (390 - x) = 35.1
0.05x + 58.5 - 0.15x = 35.1
23.4 = 0.10x
x = 234
y = 156
Answer??? I need it in under 5 mins
Answer:
The answer is 5 units.
Step-by-step explanation:
I need help ASAP please
Answer:
5:10
6 (-2,0)
7 (-5,6)
8 (5,3)
9 No, ab=8 CD=6
Step-by-step explanation:
how do i find the area of a cone when all i get is radius and theta? radius = 5 theta = 52°
Answer:
11.34464...
Step-by-step explanation:
it is not a 3-dimensional cone, it is a 2-dimensional segment of a circle. and you need to find its area.
which is also why you are asked to find the area, because for a 3-dimensional object you would have been asked about the volume of the surface.
now, about a circle and its segments.
you know how to get the area of a circle ?
it is pi×r²
that is for the full circle.
you know how many degrees it is to go "full circle" ?
360 degrees.
so, here we have only a segment of 52 degrees out of the full 360 degrees.
in other words we are dealing with 52/360 = 13/90 of the full circle.
all we have to do is therefore multiply the area of the full circle with that fraction, and we have our result.
pi×r²×13/90 = pi×5²×13/90 = pi×5×13/18 = 11.34464...
Hey good morning I need help ASAP thank you guys
Answer:
A 59
Step-by-step explanation:
Higher sample size is generally always more accurate
Which number would be rounded UP to the nearest ten but DOWN to the nearest hundred?
A. 232
B. 238
C. 262
D. 268
Answer:
B
Step-by-step explanation:
Which of the following rational functions is graphed below?
10
- 10
10
tho
A. F(x) =
3
X-7
B. F(x) = x + 3
X-7
C. F(x) =
(x+3)(x-7)
(x+3)(x-7)
D. F(X)
1
(x + 7(x-3)
7\x-
Check the picture out and please help me lol
Vertical asymptote:
A vertical asymptote is a value of x for which the function is not defined, that is, it is a point which is outside the domain of a function;
In a graphic, these vertical asymptotes are given by dashed vertical lines.
An example is a value of x for which the denominator of the function is 0.
In this graphic:
Dashed vertical lines at: [tex]x = -3, x = 7[/tex], thus, for [tex]x - (-3) = x+3[/tex] and [tex]x - 7[/tex] the denominator is zero.
Thus, the function graphed is:
[tex]F(x) = \frac{1}{(x+3)(x-7)}[/tex]
And the correct answer is given by option C.
To take a look at a problem with asymptote, you can check this item https://brainly.com/question/4084552.
The graph is for the rational function f(x) = 1/(x + 3)(x - 7).
Option C is the correct answer.
We have,
To understand the graph of the function f(x) = 1/((x + 3)(x - 7)).
Vertical Asymptotes:
The function has vertical asymptotes at the values of x for which the denominator becomes zero.
The denominator is (x + 3)(x - 7), so the vertical asymptotes occur at
x = -3 and x = 7.
Horizontal Asymptote:
The highest power of x in the denominator is x², and there is no x² term in the numerator, the function approaches 0 as x goes to positive or negative infinity.
The horizontal asymptote is y = 0.
x-Intercept:
To find the x-intercept, we set y = 0 and solve for x:
0 = 1/((x + 3)(x - 7))
Since the numerator can never be zero, the only way the fraction can be zero is if the denominator is zero:
(x + 3)(x - 7) = 0
Solving for x:
x + 3 = 0
x = -3
x - 7 = 0
x = 7
So, the x-intercepts are (-3, 0) and (7, 0).
y-Intercept:
To find the y-intercept, we set x = 0:
f(0) = 1/((0 + 3)(0 - 7)) = 1/(-3 * -7) = 1/21
The y-intercept is (0, 1/21).
Thus,
The graph is for the rational function f(x) = 1/(x + 3)(x - 7).
Learn more about functions here:
https://brainly.com/question/28533782
#SPJ6
Solve for x in the diagram
Answer:
x = 20°
Step-by-step explanation:
x + 2x + (x+10) =90° {being a right angle triangle}
3x + x + 10 = 90°
or, 4x = 90° - 10°
or, 4x = 80°
or, x = 80°/4
so, x = 20°
Help me! Thanks!!!!!!
Answer:
there are infinite solutions
Step-by-step explanation:
if you add y-3 to both sides of the first equation, you will see that it is equal to the second equation, so they are the same line. Therefore, there are infinite solutions to this system
Which of the following has the least value?
30% of 50
O 50% of 30
30% of 30
50% of 50
Answer:
30% of 30 has the least value out of all answer choices.
Step-by-step explanation:
Solve for the values of the given percentages of each number:
30% of 50:
Divide 50 by 100 to get 1%
50/100 = 0.5
Multiply 1% (0.5) by 50:
0.5 x 50 = 15
So 30% of 50 = 15
50 % of 30:
50% of a number means half of it since 50% is half of 100% so:
30/2 = 15
So 50% of 30 = 15
30% of 30:
Divide 30 by 100 to get 1%:
30/100 = 0.3
Multiply 1% (0.3) by 30:
0.3 x 30 = 9
So 30% of 30 = 9
50% of 50
50% of a number means half of it since 50% is half of 100% so:
50/2 = 25
So 50% of 50 = 25
Let’s arrange all of the values from greatest to least (left to right) to determine the most least value:
25, 15, 15, 9
9 is the most least, it is the value equal to the answer choice “30% of 30”
HOPE THIS HELPED!
Supervisor: "I need you to increase the number of customers you talk to daily by
20%."
Employee: "I talk to an average of 8 customers per hour during an 8 hour shift so
now I'll need to talk to customers per day."
68
77
85
97
160
NEXT
Answer:
77
Step-by-step explanation:
Currently:
Talk to 8 customers per hour, work 8 hours, so:
Talk to 8*8 = 64 customers.
With the increase:
Has to increase by 20%, so 64 is multiplied by 1 + 0.2 = 1.2. Then
64*1.2 = 76.8
Rounding up, 77 is the answer.
Please I need the answer according to steps
Answer:
Factorise out x and y terms:
[tex]{ \tt{ = \frac{ {x}^{2} {y}^{4} (5x - 3y)}{45} }} \\ [/tex]
I need help this is confusing to me
Answer:i think it is b not really sure
Step-by-step explanation:
Find x on this special right triangle
Answer:
the ans is 45⁰ BC it is a right angle
Step-by-step explanation:
Is this a trigonometry ratio
Find the area of the circle around your answer to the nearest 10th
Answer:
A= π ( 3.8)^2
A= 45.36
OAmalOHopeO
Step-by-step explanation:
area is 2xr(times your answer)
solve the following equations
Answer:
x=0,5/2
Step-by-step explanation:
Why does cube root 7 equal 7 to the 1/3 power
Answer:
Step-by-step explanation:
Here's how you convert:
[tex]\sqrt[n]{x^m}=x^{\frac{m}{n}[/tex] The little number outside the radical, called the index, serves as the denominator in the rational power, and the power on the x inside the radical serves as the numerator in the rational power on the x.
A couple of examples:
[tex]\sqrt[3]{x^4}=x^{\frac{4}{3}[/tex]
[tex]\sqrt[5]{x^7}=x^{\frac{7}{5}[/tex]
It's that simple. For your problem in particular:
[tex]\sqrt[3]{7}[/tex] is the exact same thing as [tex]\sqrt[3]{7^1}=7^{\frac{1}{3}[/tex]
I need help ASAP please!
Answer:
Option C
We need to make the negative exponent positive.
The rule is: [tex]A^{-B} =\frac{1}{A^{B} }[/tex]
Here, A=x, B= 12
[tex]so,[/tex] [tex]x^{-12}[/tex]
[tex]=\frac{1}{x^{12} }[/tex]
OAmalOHopeO
A store is having a sale on chocolate chips and walnuts. For 8 pounds of chocolate chips and 3 pounds of walnuts, the total cost is $34. For 2 pounds of chocolate chips and 5 pounds of walnuts, the total cost is $17. Find the cost for each pound of chocolate chips and each pound of walnuts.
Answer:
chocolate chips are $2.00 per pound.
nd walnuts must be $3.50 per pound.
Step-by-step explanation:
Let x be the price of walnuts and y the price of chocolate chips.
2x + 5y = 17 (i)
8x + 3y = 34 (ii)
Multiply (i) by 4 to get
8x + 20y = 68
Subtract (ii) to get
17y = 34
Dividing by 17, we see that chocolate chips are $2.00 per pound.
Substituting y=2 in (i) or (ii), walnuts must be $3.50 per pound.
which polygon will NOT tessellate a plane?
Step-by-step explanation:
the answer is regular octagon
i think
Simplify: −4(b+6)−2b(1−4b
Step-by-step explanation:
-4b-24-2b+8b2
8b2-6b-24=0
please help me with this question!
Answer:
12 miles
Step-by-step explanation:
Let the amount of hours it takes Leroy to catch up to Kevin equal x. Since speed multiplied by time is distance, Leroy would have run a total of 6x miles(6*x). Kevin already had a head start of 24 minutes, which is the same as 2/5 of an hour. In 2/5 an hour, Kevin ran 2 miles as 2 is 2/5 *5. For the next x hours his distance would be a total of 5x(5*x). This means, after x hours, Kevins distance is 5x + 2. In this case, catching up to someone is the same as having the same distance value. This means we can set the two expressions equal to each other, and solve:
6x = 5x + 2
x = 2
The time it took Leroy to catch up is 2 hours, but we are looking for the distance, which is represented by 6x. We substitute in 2 to get:
6(2) = 12
This means Leroy had to run 12 miles.
Please help
A. SAS
B. AAS
C. HA
D. LL
E. ASA
F. HL
Answer:
Option B, AAS
Option C, HA
Option E, ASA
these three options applies
