A magazine includes a report on the energy costs per year for32-inch liquid crystal display (LCD) televisions. The article states that 14 randomly selected 32-inch LCD televisions have a sample standard deviation of $3.42 . Assume the sample is taken from a normally distributed population. Construct 98 % confidence intervals for (a) the population variance sigma squared and (b) the population standard deviation sigma .
Interpret the results. (a) The confidence interval for the population variance is (___,___ ). (Round to two decimal places as needed.)
Interpret the results. Select the correct choice below and fill in the answer box(es) to complete your choice. (Round to two decimal places as needed.)
A. With 98 % confidence, you can say that the population variance is less than ___.
B. With 2 % confidence, you can say that the population variance is between nothing and ___ .
C. With 98 % confidence, you can say that the population variance is between ___ and ___ .
D. With 2 % confidence, you can say that the population variance is greater than ___
(b) The confidence interval for the population standard deviation is (n___,___). (Round to two decimal places asneeded.)
Interpret the results. Select the correct choice below and fill in the answer box(es) to complete your choice. (Round to two decimal places as needed.)
A. With 98% confidence, you can say that the population standard deviation is between ___ and ___ dollars per year.
B. With 98% confidence, you can say that the population standard deviation is greater than ___ dollars per year.
C. With 2% confidence, you can say that the population standard deviation is less than ___ dollars per year.
D. With 2% confidence, you can say that the population standard deviation is between ___ and ___ dollars per year.
Answer:
a
The confidence interval for the population variance is [tex] 5.49 < \sigma^2 < 37.02 [/tex]
The correct option is C
b
The confidence interval for the population standard deviation is [tex] 2.34 < \sigma < 6.08 [/tex]
The correct option is A
Step-by-step explanation:
From the question we are told that
The sample size is n = 14
The standard deviation is [tex]s = \$3.42[/tex]
Generally the degree of freedom is mathematically represented as
[tex]df = 14 -1[/tex]
=> [tex]df = 13 [/tex]
Given that the confidence level is 98% then that level of significance is
[tex]\alpha = (100 -98) \%[/tex]
=> [tex]\alpha = 0.02[/tex]
Generally the 98% confidence interval for the variance is mathematically represented as
[tex]\frac{(n- 1) s^2}{x^2 _{[\frac{\alpha }{2} , df]}} < \sigma^2 < \frac{(n- 1) s^2}{x^2 _{[1- \frac{\alpha }{2} , df]}}[/tex]
=> [tex]\frac{(14- 1) (3.42)^2}{x^2 _{[\frac{0.02 }{2} , 13]}} < \sigma^2 < \frac{(14- 1) (3.42)^2}{x^2 _{[1- \frac{0.02 }{2} , 13]}}[/tex]
From the chi -distribution table
[tex]x^2 _{[1- \frac{0.02 }{2} , 13]} = 4.107[/tex]
and
[tex]x^2 _{[\frac{0.02 }{2} , 13]} = 27.689[/tex]
So
=> [tex]\frac{(14- 1) (3.42)^2}{27.689} < \sigma^2 < \frac{(14- 1) (3.42)^2}{4.107}[/tex]
=> [tex] 5.49 < \sigma^2 < 37.02 [/tex]
Generally the 98% confidence interval for the standard deviation is mathematically represented as
[tex]\sqrt{\frac{(n- 1) s^2}{x^2 _{[\frac{\alpha }{2} , df]}}} < \sigma <\sqrt{ \frac{(n- 1) s^2}{x^2 _{[1- \frac{\alpha }{2} , df]}}}[/tex]
=> [tex]\sqrt{5.49} < \sigma < \sqrt{37.02 }[/tex]
=> [tex] 2.34 < \sigma < 6.08 [/tex]
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Coffee costs $9 per pound. How much does 600 pounds of coffee cost?
Answer:
11.400 dollars... is the answer
Answer:
$5400
Step-by-step explanation:
9 x 600 = 5400
The toco toucan, the largest member of the toucan family, possesses the largest beak relative to body size of all birds. This exaggerated feature has received various interpretations, such as being a refined adaptation for feeding. However, the large surface area may also be an important mechanism for radiating heat (and hence cooling the bird) as outdoor temperature increases. Here are data for beak heat loss, as a percent of total body heat loss, at various temperatures in degrees Celsius:
Temperature (degrees Celsius) 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Percent heat loss from beak 35 36 38 28 41 43 55 46 39 54 45 58 60 56 62 67
a. The equation of the least-squares regression line for predicting beak heat loss, as a percent of total body heat loss from all sources, from temperature is: _____ (Use decimal notation. Give your answer to four decimal places.)
b. Use the equation to predict (
±
0.01) beak heat loss, as a percent of total body heat loss from all sources, at a temperature of 25 degrees Celsius.
c. What percent (
±
0.01) of the variation in beak heat loss is explained by the straight-line relationship with temperature?
d. Find the correlation r (
±
0.001) between beak heat loss and temperature.
Answer:
Kindly check explanation
Step-by-step explanation:
Given the data:
Temperature (degrees Celsius) : 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Percent heat loss from beak : 35 36 38 28 41 43 55 46 39 54 45 58 60 56 62 67
Using an online regression calculator ; the regression equation obtained is :
ŷ = 2.0927X + 0.6029
X = independent variable
Y = predicted variable
2.0927 = slope
0.6029 = intercept
B.) temperature = 25
ŷ = 2.0927(25) + 0.6029
= 52.9204
C.) the explained variance is the value of the coefficient of determination (R²) which is the square of the correlation Coefficient
0.8785² = 0.7718
D.) the correlation Coefficient r is 0.8785 using the Coefficient of regression calculator
Three high school participated in a study to evaluate the effectiveness of a new computer-based mathematics curriculum. Four 24-student sections of freshman algebra were available for the study. The two types of instruction (standard curriculum, computer-based curriculum) were randomly assigned to the four sections in each of the three schools. At the end of the term, a standard mathematics achievement test was given to each of the 24 students in each section.
a. Is this study experimental, observational, or mixed experimental and observational? Why?
b. Identify important factors, factor levels, and/or factor-level combinations.
c. Classify these factors as within- or between-subjects
d. what’s the dependent measures?
e. What is the basic experiment unit of study?
Answer:
Given that;
There are three high schools, each having four sections of every 24 students
the 2 types of instructions are Standard curriculum & computer based curriculum
a)
this study is experimental
this is because the study did not just observe the student's performance but randomly assign the performance to different techniques that have some certain control over the technique of teaching and then observe their performance afterwards
b)
-important factors are; high schools, instruction type and scores
- Highschool has 2 levels: level one there are three high schools, level 2 each having four sections of every 24 students
-instruction type: has one level which is divided into two namely; standard base and computer based
Scores: doesn't have levels
c)
there are 3 schools and 4 sections so the factor high school has between subjects components
factor instruction type also has between subjects because there are two different types available
there are 24 students in each section which are within subjects
d)
the score on the test is the dependent measures
e)
“STUDENT” in each section is he basic experiment unit of study
Divide: 3/8 ÷ 5/12 = ?
flip 5/12 to be 12/5 to make this equation multiplication
3/8*12/5 = 36/40 = 18/20 = 9/10
The solution of expression is,
⇒ 9 / 10
We have to given that;
To Divide,
⇒ 3/8 ÷ 5/12
Now, We can divide the numbers as;
⇒ 3/8 ÷ 5/12
⇒ 3/8 × 12/5
⇒ 36 / 40
⇒ 18/20
⇒ 9 / 10
Thus, The solution of expression is,
⇒ 9 / 10
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|-9×+7|+8 is less than or equal to 9
Answer:
I don’t think it’s neither less than it equal
Step-by-step explanation:
I could be wrong don’t listen to me :)
Condense to a single logarithm: 4 log9 11 - 4 log9 7.
O log9, (44/28)
O log9, (11/7)^4
O log9, (11/28)
log9 (44/7)
Answer: Log9,(11/7)^4
Step-by-step explanation:
according to the rules of logarithm
1)Subtraction sign(-) becomes division(÷),while addition(+)becomes multiplication (x)
2) the number in front of the log figure becomes an indices
Answer:
log9 (11/7)4
Step-by-step explanation:
got it right on the test
Find both the greatest common factor and the least common multiple of 24 and 30.
Answer:
24 = 2, 3 , 4, 6, 8, 12, 24
30 = 2, 3, 5, 6, 10, 15, 30
Step-by-step explanation:
Least common for both is 2
Greatest common factor for both is 6
Megan had $235.17 in her bank account. She withdrew $77.98 from the account to spend
on clothing. How much money does she have left in her bank account now?
Answer: 157.19
Step-by-step explanation:
f(x) = x + 7, g(x) = x - 7
(a) (f + g)(x) =
(b) (f-g)(x)=
(c) (fg)(x)=
(d) (f/g)(x)=
a) 2x
b) 14
c) x^2 -49
d) -1
Can someone explain the snake method, I don't understand how to do it
Answer:
x ∈ [−2; 1] ∪ 3.5Step-by-step explanation:
GivenInequality: (x-1)(x+2)(2x-7)≤0
Solution:If we solve the corresponding equation (x-1)(x+2)(2x-7)²= 0, we get roots
x = -2, 1, 3.5We need to consider the following 4 intervals:
(−∞; −2), [−2; 1], (1; 3.5), (3.5; ∞)1st interval (−∞; −2)
The expression (x-1)(x+2)(2x-7)² is positive as two of the multiples are negative and one is always positive (square number), and therefore does not satisfy the inequality.2nd interval [−2; 1]
The expression is negative as only one of the multiples is negative, and therefore the interval (−1; 2) satisfies the inequality.3rd interval (1; 3.5)
The expression is positive as all the multiples are positive. Therefore, the interval (1; 3.5) also does not satisfy the inequality.4th interval
The expression is positive as above, and therefore also does not satisfy the inequality.So, the answer to the inequality is:
x ∈ [−2; 1] ∪ 3.5Help, Plz explain!!!
Answer:
B. 40
Step-by-step explanation:
y varies directly as x
y=kx, k is a constant
when x=8, y=5. k*8=5
k=5/8
When x=64,
y= 5/8 * 64
y= 40
Answer:
I think the answer will be C 61
Step-by-step explanation:
y=5 when x=8
8-3=5
x=64 y=?
64-3=61
HURRY PLEASE HELP
What is the approximate distance from the origin to the point (−10, −4, 5)? Round to the nearest tenth. 4.4 units 10.4 units 11.9 units 19.0 units
The answer is 11.9 units
First you must set up the distance formula.
[tex]\sqrt[]{ (-10-0)^2+(-4-0)^2+(5-0)^2}[/tex]
Then, simplify like terms.
[tex]\sqrt{(-10)^2+(-4)^2+(5)^2}[/tex]
Next, simplify exponents.
[tex]\sqrt{100+16+25}[/tex]
Then, add like terms.
[tex]\sqrt{141}[/tex]
Finally, round to the nearest tenth.
11.9
There are two squares.
The larger square has an area of 1,089 square feet and the smaller square has an area of 121 square inches.
What is the scale factor between the two squares?
(A) 3
B
6
12
D 36
Answer:
It is 3
Step-by-step explanation:
Answer:
It is 3
Step-by-step explanation:
which equation choice could represent the graph shown below?
Answer:
The answer is...
f(x)=(x-3)+(x+3)
I think this is the answer. I haven't done this kind of math in a while so...
The chosen equation, (x +3)(x + 3) = 0, will serve as a representation of the provided graph.
What is a Quadratic equation?ax²+bx+c=0, with a not, equals 0 is a quadratic equation, which is a second-order polynomial equation in a single variable. It has at least one solution because it is a second-order polynomial equation, which is guaranteed by the algebraic fundamental theorem. The answer could be simple or complicated.
given a Graph of a quadratic equation.
Contrarily, parabolas are used to graph quadratic equations. In other words, the data will be displayed as either an "open" or "upside-down" U-shaped curve. The graph is always quadratic if you are drawing a graph from a function and the equation involves x².
in this graph, we can observe that graph has only one root at x = -3
therefore the equation of the Given parabola is
(x + 3)² = 0
or
(x +3)(x + 3) = 0
therefore, the equation choice could represent the graph given will be (x +3)(x + 3) = 0.
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Plz do fast I need it for a test The front view of a tent is.shown below if a zipper.is going to be put in along the length x how long should the.zipper be
Answer:
x=15ft
Step-by-step explanation:
a^2+b^2=c^2
8^2+b^2=17^2
b^2+64=289
b^2=225
b=15
I need help with this question
Answer:
b
Step-by-step explanation:
A light bulb consumes 3450 watt-hours-in 5 days and 18 hours. How many watt-hours does it consume per day
Answer:
5 days = 5 * 24 = 120 hours
120 + 18 = 138hours
3450/138 * 24 = 600 watt hours
600watt hours
Does anyone know this answer
Need help ASAP with my math
Answer: The answer is -2
Step-by-step explanation: I want points and trust me this answer is correct
3.89×10^9 in standard form
Answer:
3890000000
Step-by-step explanation:
Evaluate 8 ÷ -2 · 4²+9. Thanks! Will give brainiest if possible
9. Determine whether KM and ST are parallel, perpendicular, or neither. K(-1, -8), M(1,6), S(-2,-6), T(2, 10) A Parallel B Perpendicular C Neither Hint(use slope formula)
if a person ran 1/2 of a mile in 1/10 of an hour. How far will the person run in one (1) hour?
Step-by-step explanation:
In 1/10 of 1hr = 1/2 mile
10*(1/10) of 1hr = 10(1/2) mile
(10/10) of 1hr = (10/2) mile
1 of 1hr = 5mile
It says, he can run 5 miles in 1 hour
Given the equation 5(-2x -10) = 25(x + 1), solve for the value of x that will make the equation true.
Answer:
Step-by-step explanation:
5(-2x -10) = 25(x + 1)
-10x - 50 = 25x + 25
by transposing
-10x - 25x = 25 + 50
-35x = 75
x = -75/35
x = 15/7
or 2.142857..... in decimal
Hope this helps
plz mark as brainliest!!!!!!!
find m ABC (2x) (5x+5)
Answer:
=130
Step-by-step explanation:
(2x) (5x+5) = 180
7x + 5 = 180
7x = 175
x = 25
5(25) + 5 = 125 + 5 = 130
Hope this helps (:
If a person walks 1/3 of a mile every 1/6 of an hour, what is their speed in miles per hour?
Answer:
2 mi per hour
Step-by-step explanation:
1/3*6=
6/3= 2
2 mi per hour
Answer:
2mph
Step-by-step explanation:
If a person walks 1/3 of a mile every 1/6 of an hour you divide to solve.
[tex]\frac{\frac{1}{3}}{\frac{1}{6}}[/tex] To solve you flip the bottom and multiply:
[tex]\frac{1}{3} *\frac{6}{1}[/tex] = [tex]\frac{6}{3} = 2[/tex]
The person is walking 2mph
An avant-garde clothing manufacturer runs a series of high-profile, risque ads on a billboard on Highway 101 and regularly collects protest calls from people who are offended by them. The company has no idea how many people in total see the ad, but it has been collecting statistics on the number of phone calls from irate viewers:
Answer and Step-by-step explanation:
Please find attached
Tara's website, verdantveggies.com, specializes in the sale of rare or unusual vegetable seeds. Tara sells packets of sweet-pepper seeds for $2.85 each and packets of hot-pepper seeds for $4.29 each. She also offers a 16-packet mixed-pepper assortment combining packets of both types of seeds at $3.30 per packet. How many packets of each type of seed are in the assortment?
Answer:
Let's define the variables:
S = # of sweet pepper seeds in the mix pack.
H = # of hot pepper seeds in the mix pack.
Let's suppose that $3.30 is the mean price of the seeds in the mix pack.
Then we have two equations:
S + H = 16.
(S*$2.85 + H*$4.29)/16 = $3.30
Now let's solve this system.
The first step is isolating one variable in one of the equations, i will isolate S in the first equation.
S = 16 - H.
Now we can replace this in the second equation, and solve it for H.
( (16 - H)*$2.85 + H*$4.29)/16 = $3.30
( (16 - H)*$2.85 + H*$4.29) = $3.30*16 = $52.80
$45.60 + H*$1.44 = $52.80
H*$1.44 = $52.80 - $45.60 = $7.20
H = $7.20/$1.44 = 5
Then in the mix pack there are 5 hot-pepper seeds.
And the other 11 must be sweet-pepper seeds
Algebraic equations are equations that contain unknown variables.
The number of packets of sweet-pepper seeds is 11 and the number of packets of hot-pepper seeds is 5.
Let's represent:is
The number of packets of sweet-pepper seeds = s
The number of packets of hot-pepper seeds = h
Based on this question, our system of equations are:
$2.85 x s + $4.29 x h = $3.30(16)
2.85s + 4.29h = 52.8...........Equation 1
s + h = 16...........Equation 2
s = 16 - h
We substitute 16 - h for s in Equation 1
2.85(16 - h) + 4.29h = 52.8
45.6 -2.85h + 4.29h = 52.8
Subtract 45.6 from both sides
45.6 - 45.6 -2.85h + 4.29h = 52.8 - 45.6
1.44h = 7.2
h = 5
There are 5 hot-pepper seeds in the assortment.
Solving for the number of sweet-pepper seeds.
s = 16 - h
s = 16 - 5
s = 11
There are 11 sweet-pepper seeds in the assortment.
Therefore, the number of packets of sweet-pepper seeds is 11 and the number of packets of hot-pepper seeds is 5.
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The correct Standard Form of the equation y=−2/7x−11/7
Answer:
y=-(2)/(7)x-5
Step-by-step explanation: