Answer:
Brainleist!
Step-by-step explanation:
vertex (h,k)
h= -b/4a
k= c -b^2/4a
solve and you get (2,17)
You find 72 coins consisting only of nickels, dimes, and quarters, with a face value of $10.20. However, the coins all date from 1919, and are worth considerably more than their face value. A coin dealer offers you $10 for each nickel, $20 for each dime, and $15 for each quarter, for a total of $1,060. How many nickels did you find?
Answer:
You have found 24 nickels.
Step-by-step explanation:
Let N be the number of nickles, D be the number of dimes and Q be the number of quarters. The number of coins and their face values are given by the following expressions, respectively:
[tex]N+D+Q=72\\0.05N+0.10D+0.25Q=10.20[/tex]
As of now we have three variables and two expressions, the final expression needed to solve the linear system is given by the amount offered by the coin dealer:
[tex]10N+20D+15Q=1,060[/tex]
Solving the linear system:
[tex]N+D+Q=72\\5N+10D+25Q=1,020\\10N+20D+15Q=1,060\\\\10N-10N+20D-20D+15Q-50Q=1,060-(2*1,020)\\-35Q=-980\\Q=28\\\\5N-10N+10D-10D+25Q-10Q=1,020-720\\-5N+15Q=300\\-5N=300-(15*28)\\N=24[/tex]
You have found 24 nickels.
2x+y=1 and
2x + 4y = 12
Graph the system of equations
Answer:
see below for a graph
Step-by-step explanation:
A graphing calculator makes this short work.
__
You can find the x- and y-intercepts by setting the opposite variable to zero.
First equation x-intercept is the solution to 2x +0 = 1: x = 1/2. The y-intercept of that equation is the solution to 2·0 +y = 1: y = 1. The graph is the line through these points.
Second equation x-intercept is the solution to 2x +4·0 = 12: x = 6. The y-intercept is the solution to 2·0 +4y = 12: y = 3. The graph is the line through these points.
Antipsychotic drugs are widely prescribed for conditions such as schizophrenia and bipolar disease. An article reported on body composition and metabolic changes for individuals who had taken various antipsychotic drugs for short periods of time. (a) The sample of 41 individuals who had taken aripiprazole had a mean change in total cholesterol (mg/dL) of 3.55, and the estimated standard error sD n was 3.478. Calculate a confidence interval with confidence level approximately 95% for the true average increase in total cholesterol under these circumstances. (Round your answers to two decimal places.)
Answer:
95% for the true average increase in total cholesterol under these circumstances
(-2.306 , 9.406)
Step-by-step explanation:
Step(i):-
Given sample size 'n' =41
Mean of the sample(x⁻) = 3.55
The estimated standard error
[tex]S.E = \frac{S.D}{\sqrt{n} }[/tex]
Given estimated standard error ( S.E) = 3.478
Level of significance ∝=0.05
Step(ii):-
95% for the true average increase in total cholesterol under these circumstances
[tex](x^{-} - t_{0.05} S.E ,x^{-} + t_{0.05} S.E)[/tex]
Degrees of freedom
ν= n-1 = 41-1 =40
t₀.₀₅ = 1.6839
95% for the true average increase in total cholesterol under these circumstances
[tex](x^{-} - t_{0.05} S.E ,x^{-} + t_{0.05} S.E)[/tex]
( 3.55 - 1.6839 ×3.478 ,3.55 + 1.6839 ×3.478 )
(3.55 - 5.856 , 3.55 + 5.856)
(-2.306 , 9.406)
Conclusion:-
95% for the true average increase in total cholesterol under these circumstances
(-2.306 , 9.406)
What is the surface area of the pyramid? 12ft 10ft 10ft
Answer:
2h x (l+b)
2x10 X (12+10)
20 X 22
44 cm cube is your answer...
angle ∠DAC= angle ∠BAD. What is the length of BD? Round to one decimal place.
Answer: 3.9
Step-by-step explanation: Khan Academy
The length of BD if The angle ∠ DAC is equal to the angle ∠ BAD is 3.92.
What is the triangle?Three straight lines coming together create a triangle. There are three sides and three corners on every triangle (angles). A triangle's vertex is the intersection of two of its sides. Any one of a triangle's three sides can serve as its base, however typically the bottom side is used.
Given:
The angle ∠ DAC = angle ∠ BAD
As we can see that the triangle BAD and triangle DAC are similar By SAS similarity,
AC / AB = CD / BD (By the proportional theorem of similarity)
5.6 / 5.1 = 4.3 / BD
1.09 = 4.3 / BD
BD = 4.3 / 1.09
BD = 3.92
Thus, the length of BD is 3.92.
To know more about Triangles:
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I need help PLEASE help mee
Answer:
Step-by-step explanation:
In order to convert 0.0004578, which is in decimal, to scientific notation, all we need to do in this case is to move our decimal point to the right till we arrive at the first number that is not a zero, and then eliminate all the zero.
In this case, we will have to move the decimal point 4 spaces to our right, which would mean our exponent would be negative. The number of decimal spaces we moved to our right would be the value of our exponent, which is -4 in this case.
Thus, we have:
[tex] 4.578 * 10^{-4} [/tex]
A sociologist is studying the number of years of education of students whose mothers have bachelor's degrees or higher. The data is normally distributed with a population mean of 14.5 years and a population standard deviation of 2.5 years. If a sample of 55 students is selected at random from the population, select the mean and standard deviation of the sampling distribution below.
a. σi= 0.05 years
b. σi= 2.5 years
c. σi= 0.34 years
d. µ= 14.5 years
Answer:
The mean of the sampling distribution is 14.5 years and the standard deviation is 0.34 years.
Step-by-step explanation:
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
Population:
[tex]\mu = 14.5, \sigma = 2.5[/tex]
Sample:
55 students, so [tex]n = 55[/tex]
Then
[tex]\mu = 55, s = \frac{2.5}{\sqrt{55}} = 0.34[/tex]
The mean of the sampling distribution is 14.5 years and the standard deviation is 0.34 years.
The assembly time for a product is uniformly distributed between 8 and 12 minutes.The mean and the variance of the assembly time are: a.4 minutes and 16 (minute)2 b.8 minutes and 12 (minute)2 c.12 minutes and 1.33 (minute)2 d.10 minutes and 1.33 (minute)2
Answer:
d. 10 minutes and 1.33 minutes.
Step-by-step explanation:
An uniform probability is a case of probability in which each outcome is equally as likely.
For this situation, we have a lower limit of the distribution that we call a and an upper limit that we call b.
The mean of the uniform distribution is:
[tex]M = \frac{a + b}{2}[/tex]
The variance of the uniform distribution is given by:
[tex]V = \frac{(b-a)^{2}}{12}[/tex]
The assembly time for a product is uniformly distributed between 8 and 12 minutes.
This means that [tex]a = 8, b = 12[/tex].
Mean:
[tex]M = \frac{8 + 12}{2} = 10[/tex]
Variance:
[tex]V = \frac{(12-8)^{2}}{12} = 1.33[/tex]
So the correct answer is:
d. 10 minutes and 1.33 minutes.
Diana works in a building that is 130 feet tall. She is outside, looking up at the building at an angle of 37° from her feet to the top of the building. If Diana walks forward and her angle looking to the top of the building changes to 40°, how much closer is she to the building? Round the answer to the nearest tenth of a foot.
Answer:
Let x be her initial distance from the building, then tan 37 = 130/x
x = 130/tan 37 = 130/0.7536 = 172.5 feet
Let y be her distance from the building after moving forward, then
tan 40 = 130/y
y = 130/tan 40 = 130/0.8391 = 154.9
After moving forward, she is 172.5 - 154.9 = 17.6 ft closer.
Answer: B. 17.6 ft.
Step-by-step explanation: I just did it on the edge 2023 assignment. Check attached image.
help plz!!!! 30 points!!!!!!!!!! i will mark brainliest for who answers first! anveer bought 0.7 pounds of sliced ham at his local deli. If the deli charged $6.79 per pound, how much did Tanveer pay? A. $2.04 B. $4.75 C. $7.49 D. $9.70
Answer:
B
Step-by-step explanation:
[tex]6.79 \times 0.7[/tex]
[tex]=4.753[/tex]
Answer:
The correct answer would be $4.75
Step-by-step explanation:
6.79 × 0.7
=$4.75
Hope that was helpful.Thank you!!!
The computer rendering of a mural in a town's square uses
the function represented in the table to define the outline of
a mountain in the town's logo, where x is the distance in
feet from the edge of the mural and f(x) is the distance from
the ground in feet.
How can the point (12, 16) be explained?
The highest point of the mountain defined by the
function is 12 feet.
The highest point of the mountain defined by the
function is 16 feet.
The width of the base of the mountain defined by the
function is 12 feet.
The width of the base of the mountain defined by the
function is 16 feet.
f(x)
-16
4
8
0
10
8
12
16
20
--16
Answer:
B
The highest point of the mountain defined by the function is 16 feet.
ED 2020
Step-by-step explanation:
The highest point of the mountain defined by the function is 16. Therefore, option B is the correct answer.
What is the function?Functions are the fundamental part of the calculus in mathematics. The functions are the special types of relations. A function in math is visualized as a rule, which gives a unique output for every input x.
From the given information, we have;
The distance in feet from the edge of the mountain is given as the independent variable, x
The distance in feet from the ground (which is the height) is given the as the dependent variable f(x)
Therefore, given that the point (12, 16) are the values of x and f(x) such that x = 12 and f(x) = 16 and 16 is the largest value of f(x) in the data, therefore, 16 represents the highest defined point of the mountain.
Therefore, option B is the correct answer.
To learn more about the function visit:
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"Your question is incomplete, probably the complete question/missing part is:"
The computer rendering of a mural in a town’s square uses the function represented in the table to define the outline of a mountain in the town’s logo, where x is the distance in feet from the edge of the mural and f(x) is the distance from the ground in feet. How can the point (12, 16) be explained?
A) The highest point of the mountain defined by the function is 12 feet.
B) The highest point of the mountain defined by the function is 16 feet.
C) The width of the base of the mountain defined by the function is 12 feet.
D) The width of the base of the mountain defined by the function is 16 feet.
Please answer this correctly
Answer:
47
Step-by-step explanation:
The probability for tails to land is 1/2 when you flip 1 coin.
When you flip 94 times, 1/2 × 94
= 47
A sample of 75 information systems managers had an average hourly income of $40.75 with a standard deviation of $7.00. The 95% confidence interval for the average hourly wage (in $) of all information system managers is
Answer:
The 95% confidence interval for the average hourly wage of all information system managers is (39.14,42.36)
Step-by-step explanation:
In order to calculate the 95% confidence interval for the average hourly wage we would have to calculate first the margin of error as follows:
ME=t0.05/2,n-1s/√n
for n=75, t0.025,74=1.993
Therefore, ME=1.993*7/√75
ME=1.61
Therefore, the 95% confidence interval for the average hourly income of all syatem manager would be as follows:
(X-ME,X+ME)=(40.75-1.61,40.75+1.61)
=(39.14,42.36)
The rates of on-time flights for commercial jets are continuously tracked by the U.S. Department of Transportation. Recently, Southwest Air had the best rate with 80 % of its flights arriving on time. A test is conducted by randomly selecting 15 Southwest flights and observing whether they arrive on time. (a) Find the probability that at least 2 flights arrive late.
Answer:
83.29% probability that at least 2 flights arrive late.
Step-by-step explanation:
For each flight, there are only two possible outcomes. Either it arrives late, or it does not arrive late. The probability of a flight arriving late is independent of other flights. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
And p is the probability of X happening.
80 % of its flights arriving on time.
So 100 - 80 = 20% arrive late, which means that [tex]p = 0.2[/tex]
15 Southwest flights
This means that [tex]n = 15[/tex]
Find the probability that at least 2 flights arrive late.
Either less than two arrive late, or at least 2 do. The sum of the probabilities of these outcomes is 1. So
[tex]P(X < 2) + P(X \geq 2) = 1[/tex]
We want [tex]P(X \geq 2)[/tex]
Then
[tex]P(X \geq 2) = 1 - P(X < 2)[/tex]
In which
[tex]P(X < 2) = P(X = 0) + P(X = 1)[/tex]
So
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 0) = C_{15,0}.(0.2)^{0}.(0.8)^{15} = 0.0352[/tex]
[tex]P(X = 1) = C_{15,1}.(0.2)^{1}.(0.8)^{14} = 0.1319[/tex]
[tex]P(X < 2) = P(X = 0) + P(X = 1) = 0.0352 + 0.1319 = 0.1671[/tex]
Then
[tex]P(X \geq 2) = 1 - P(X < 2) = 1 - 0.1671 = 0.8329[/tex]
83.29% probability that at least 2 flights arrive late.
The average height of students at UH from an SRS of 12 students gave a standard deviation of 2.5 feet. Construct a 95% confidence interval for the standard deviation of the height of students at UH. Assume normality for the data.a. (1.271, 6.245)b. (0.771, 10.245)c. (1.771, 4.245)d. (7.771, 9.245)e. (4.771, 10.245)f. None of the above
Answer:
c. [1.771;4.245] feet
Step-by-step explanation:
Hello!
The variable of interest is
X: height of a student at UH
X~N(μ;σ²)
You have to estimate the population standard deviation using a 95% confidence interval.
The statistic to use for the interval is a student Chi-Square with n-1 degrees of freedom. First you have to calculate the CI for the population variance:
[tex][\frac{(n-1)S^2}{X^2_{n-1;1-\alpha /2}} ;\frac{(n-1)S^2}{X^2_{n-1;\alpha /2}} ][/tex]
[tex]X^2_{n-1;1-\alpha /2}= X^2_{11;0.975}= 21.920[/tex]
[tex]X^2_{n-1;\alpha /2}= X^2_{11;0.025}= 3.816[/tex]
n=12
S= 2.5
[tex][\frac{11*6.25}{21.920} ;\frac{11*6.25}{3.816}} ][/tex]
[3.136; 18.016] feet²
Then you calculate the square root of both limits to get the CI for the population standard deviation:
[√3.136; √18.016]
[1.771;4.245] feet
I hope this helps!
Solve the equation and express each solution in a+bi form x^4-7x^2-8=0
Answer:
x = ±2√2, ±i
Step-by-step explanation:
Step 1: Factor
(x² - 8)(x² + 1)
Step 2: Find roots
x² - 8 = 0
x² = 8
x = ±2√2
x² + 1 = 0
x² = -1
x = ±i
Answer:
The answer is B
Step-by-step explanation:
Expand (2 + a)9 using Pascal’s triangle.
Answer:
Step-by-step explanation:
The Pascal triangle is used to determine the coefficients of the terms when we expand the expression.
1 [tex](A + B) ^ 0[/tex] = 1
1 1 [tex](A +B ) ^ 1 = 1A + 1B[/tex]
1 2 1 [tex](A+ B) ^ 2 = 1A^2 + 2 AB + 1B^2[/tex]
By extending the triangle, you will get the 9th row, which is your expression, of the coefficients. that is
1 9 36 84 126 126 84 36 9 1
Now, fill in AB in the gaps.
1AB + 9 AB + 36AB + 84AB + 126AB + 126AB +84AB + 36AB + 9AB + 1AB
Next, you need to go from the left to fill out the exponent of A and it will go down from 9 (the exponent of the whole thing) . That is
[tex]1A^9B+9A^8B+36A^7B+84A^6B+126A^5B+126A^4B+84A^3B+36A^2B+9A^1B+1A^0B[/tex]
Next will be the exponent of B. this time, you go from the right and do the same with A. You can go from the left also, but go up from 0 to 9 for the exponent of B
[tex]1A^9B^0+9A^8B^1+36A^7B^2+84A^6B^3+126A^5B^4+126A^4B^5+84A^3B^6+36A^2B^7+9A^1B^8+1A^0B^9[/tex]
The last step is just to simplify the A^0=1 and B^0 =1 at the first and the last terms.
[tex]A^9+9A^8B^1+36A^7B^2+84A^6B^3+126A^5B^4+126A^4B^5+84A^3B^6+36A^2B^7+9A^1B^8+B^9[/tex]
Hope you can learn the method
SOMEONE PLEASE HELP ME ASAP PLEASE!!!
Answer:
81.64
Step-by-step explanation:
To find the circumference of this circle we take pi or 3.14 and multiply it by 2
3.14 * 2 = 6.28
Then we multiply 6.28 by 13
6.28 * 13 = 81.64
I need help with this
Answer:
Volume = 14.5 cm³
Step-by-step explanation:
Volume of cone = [tex]\pi r^2\frac{h}{3}[/tex]
Where r = 2 and h = 3.46
Volume = [tex](3.14)(2)^2\frac{3.46}{3}[/tex]
Volume = (3.14)(4)(1.15)
Volume = 14.5 cm³
HELP ASAP GIVING BRANLIST!!
Answer:
Question 1: 3 - 5 hours.
Question 2: 0 - 1 hour
Step-by-step explanation:
Question 1: As you can see in the diagram, the guy is moving really slowly and is almost stuck, therefore, it is 3 - 5 hours.
Question 2: In hours 0 - 1, you can see that the graph is the closest to vertical as it gets.
the answer is 15 hours what is the question
Answer:
how many hours do you spend on your laptop
Answer:
the question is 17 hours - 2 hours
Arc CD is Two-thirds of the circumference of a circle. What is the radian measure of the central angle? StartFraction 2 pi Over 3 EndFraction radians StartFraction 3 pi Over 4 EndFraction radians StartFraction 4 pi Over 3 EndFraction radians StartFraction 3 pi Over 2 EndFraction radians CAN YOU SHOW WORK PLEASE
Answer:
[tex]\theta = \frac{4\pi}{3}[/tex]
Step-by-step explanation:
Given
Let A represent the Length of Arc CD and C, represents the circumference
[tex]A = \frac{2}{3} C[/tex]
Required
Find the central angle (in radians)
The length of arc CD in radians is as follows;
[tex]A = r\theta[/tex]
Where r is the radius and [tex]\theta[/tex] is the measure of central angle
The circumference of a circle is calculated as thus;
[tex]C = 2\pi r[/tex]
From the question, it was stated that the arc length is 2-3rd of the circumference;
This means that
[tex]A = \frac{2}{3} C[/tex]
Substitute [tex]2\pi r[/tex] for C and [tex]r\theta[/tex] for A
[tex]A = \frac{2}{3} C[/tex] becomes
[tex]r\theta = \frac{2}{3} * 2\pi r[/tex]
[tex]r\theta = \frac{4\pi r}{3}[/tex]
Divide both sides by r
[tex]\frac{r\theta}{r} = \frac{4\pi r}{3}/r[/tex]
[tex]\frac{r\theta}{r} = \frac{4\pi r}{3} * \frac{1}{r}[/tex]
[tex]\theta = \frac{4\pi r}{3} * \frac{1}{r}[/tex]
[tex]\theta = \frac{4\pi}{3}[/tex]
Hence, the measure of the central angle; [tex]\theta = \frac{4\pi}{3}[/tex]
Answer:
The answer is C on Edge 2020
Step-by-step explanation:
I did the assignment
PLEASE ANSWER FAST !!!
What is the range of the function g for given domain ?
Answer:
The answer is B
Step-by-step explanation:
Hope this helps.. if not im sorry :(
Change the following statements into repor
1. Jim said, "I love Spanish food."
2. Emily said, "I'm going to Singapore next month
Answer:
I love Spanish food said Jim
I'm going to Singapore next month said Emily
Answer:
1) Jim said that he loves spanish food.
2) Emily said that she is going to SINGAPORE next month.
Step-by-step explanation:
I hope it helps.
Nicola runs a small pottery cafe. Customers choose from a range of ceramics which they paint and personalise.
Nicola wants to make as much profit as possible on the sale of ceramic plates. She pays £1.28 for each plate. What is the most profit Nicola can make on one plate.
Answer:
Bb
Step-by-step explanation:
Suppose that past experience shows that about 11% of passengers who are scheduled to take a particular flight fail to show up. For this reason, airlines sometimes overbook flights, selling more tickets than they have seats, with the expectation that they will have some no shows. Suppose an airline uses a small jet with seating for 30 passengers on a regional route and assume that passengers are independent of each other in whether they show up for the flight. Suppose that the airline consistently sells 32 tickets for every one of these flights.A. Describe a random variable X. Explain carefally what distribution can be use and what are a are the values of the parameters? B. On average, how many passengers will be on each flight? C. Find the probability that at least 40 seats will be filled. D. How often will they have enough seats for all of the passengers who show up for the flight?
Answer:
(a) The average number of passengers that will be on each flight is 28.8.
(b) Everyone will have a seat on about 84.4% of the flights.
Step-by-step explanation:
The correct question is:
Suppose that past experience shows that about 10% of passengers who are schedule to take a particular flight fail to show up. For this reason, airlines sometimes overbook flights, selling more tickets than they have seats, with the expectation that they will have some no shows. Suppose an airline used a small jet with seating for 30 passengers on a regional route and assume that passengers are independent of each other in whether they show up for the flight. Suppose that the airline consistently sells 32 tickets for every one of these flights.
(a) On average, how many passengers will be on each flight?
(b) How often will they have enough seats for all of the passengers who show up for the flight?
Solution:
Let the random variable X measure the number of passengers (out of 32) who show up for a flight.
For each passenger there is a 90% chance of showing up, so X is a binomial random variable with n = 32 and p = 0.90.
(a)
The average of a binomial random variable is:
[tex]\text{Average}=np[/tex]
Compute the average number of passengers that will be on each flight as follows:
[tex]\text{Average}=np[/tex]
[tex]=32\times 0.90\\=28.8[/tex]
Thus, the average number of passengers that will be on each flight is 28.8.
(b)
To have enough seats for all of the passengers who show up for the flight, the value of X must be less than or equal to 30.
Compute the value of P (X ≤ 30) as follows:
P (X ≤ 30) = 1 - P (X > 30)
= 1 - P (X = 31) - P (X = 32)
[tex]=1-[{32\choose 31}\ (0.90)^{31}\ (1-0.90)^{32-31}]-[{32\choose 32}\ (0.90)^{32}\ (1-0.90)^{32-32}]\\\\=1-0.122087-0.034337\\\\=0.843576\\\\\approx 0.844[/tex]
Thus, everyone will have a seat on about 84.4% of the flights.
NEED GEOMETRY HELP ASAP (12 POINTS)
Answer:
HJ > PK
Step-by-step explanation:
Notice that the side PL in one triangle has the same length as side GJ in the other, and side GH has the same size as side LK of the other triangle. Now what is different is the angle subtended between these sides in the case of the triangle on the lower left, the subtended angle is [tex]90^o[/tex] , which is larger angle than that subtended between equal sides on the other triangle ([tex]85^o[/tex])
Therefore, if the angle subtended by the equivalent sides in the triangle on the left is larger than the angle subtended on the right hand side triangle, then the sides associated with such angle aperture must keep the inequality. That is:
Since [tex]\angle\,G\,\,\,>\,\,\,\angle \,L[/tex], then HJ > PK
Please answer this correctly
Find the regression equation, letting the first variable be the predictor (x) variable. Using the listed lemon/crash data, where lemon imports are in metric tons and the fatality rates are per 100,000 people, find the best predicted crash fatality rate for a year in which there are 525 metric tons of lemon imports. Is the prediction worthwhile?
Lemon Imports 226264-366-470-539-
Crash Fatality Rate 16 157 15.4 15.3 15
Answer:
The equation of regression is
[tex]y = 16.522 - 0.00279 \cdot x[/tex]
The predicted crash fatality rate is 15.057 for 525 metric tons of lemon import.
Step-by-step explanation:
We are given the following lemon/crash data,
Lemon Imports = 226 264 366 470 539
Crash Fatality Rate = 16 15.7 15.4 15.3 15
The regression equation is given by
[tex]y = a + b \cdot x[/tex]
where x is the lemon imports in metric tons and y is the fatality rate per 100,000 people.
The constants b is the slope and a is the y-intercept of the regression line and are given by
[tex]$ a = \frac{\sum Y \times \sum X^2 - \sum X \times \sum XY }{n \times \sum X^2 - (\sum X)^2} $[/tex]
[tex]$ b = \frac{n \times \sum XY - \sum X \times \sum Y }{n \times \sum X^2 - (\sum X)^2} $[/tex]
Using Excel to find [tex]\sum X, \sum Y, \sum XY, \sum X^2[/tex]
[tex]\sum X[/tex] = 1865
[tex]\sum Y[/tex] = 77.4
[tex]\sum XY[/tex] = 28673.2
[tex]\sum X^2[/tex] = 766149
So the constants a and b are
[tex]$ a = \frac{77.4 \times 766149 - 1865 \times 28673.2 }{5 \times 766149 - (1865)^2} $[/tex]
[tex]a = 16.522[/tex]
[tex]$ b = \frac{5 \times 28673.2 - 1865 \times 77.4 }{5 \times 766149 - (1865)^2} $[/tex]
[tex]b = -0.00279[/tex]
Therefore, the equation of regression is
[tex]y = a + b \cdot x \\\\y = 16.522 - 0.00279 \cdot x[/tex]
The best predicted crash fatality rate for a year in which there are 525 metric tons of lemon imports is given by
[tex]y = 16.522 - 0.00279 \cdot (525) \\\\y = 16.522 - 1.465 \\\\y = 15.057[/tex]
The predicted crash fatality rate of 15.057 for 525 metric tons of lemon import seems to be satisfactory since it lies between the crash fatality rate of 15 to 15.3 for lemon imports of 539 to 470.
A research organization keeps track of what citizens think is the most important problem facing the country today. They randomly sampled a number of people in 2003 and again in 2009 using a different random sample of people in 2009 than in 2003 and asked them to choose the most important problem facing the country today from the following choices, war, economy, health care, or other. Which of the following is the correct test to use to determine if the distribution of "problem facing this countrytoday" is different between the two different years?
A.
Use a chi-square test of homogeneity.
B.
Use a paired t-test.
C.
Use a two-sample z-test for proportions.
D.
Use a chi-square goodness-of-fit test.
Answer:
Step-by-step explanation:
From the information given, the population is divided into sub groups. Each group would consist of citizens picking a particular choice as the most important problem facing the country. The choices are the different categories. In this case, the null hypothesis would state that the distribution of proportions for all categories is the same in each population. The alternative hypothesis would state that the distributions is different. Therefore, the correct test to use to determine if the distribution of "problem facing this country today" is different between the two different years is
A) Use a chi-square test of homogeneity.