Looks like either [tex]f''(x)=4x^2[/tex] or [tex]f''(x)=\frac4{x^2}[/tex]...
In the first case, integrate both sides twice to get
[tex]f''(x)=4x^2\implies f'(x)=\dfrac43x^3+C_1\implies f(x)=\dfrac13x^4+C_1x+C_2[/tex]
Then the initial conditions give
[tex]f'(1)=2\implies 2=\dfrac43\cdot1^3+C_1\implies C_1=\dfrac23[/tex]
[tex]f(1)=5\implies 5=\dfrac13\cdot1^4+C_1\cdot1+C_2\implies C_2=4[/tex]
so that the particular solution is
[tex]f(x)=\dfrac{x^4}3+\dfrac{2x}3+4[/tex]
If instead [tex]f''(x)=\frac4{x^2}[/tex], we have
[tex]f''(x)=\dfrac4{x^2}\implies f'(x)=-\dfrac4x+C_1\implies f(x)=-4\ln|x|+C_1x+C_2[/tex]
[tex]f'(1)=2\implies 2=-\dfrac41+C_1\implies C_1=6[/tex]
[tex]f(1)=5\implies 5=-4\ln|1|+C_1\cdot1+C_2\implies C_2=-1[/tex]
[tex]\implies f(x)=-4\ln|x|+6x-1[/tex]
The company charges $5 per sq ft, AND has a minimum charge of 3 sq ft per order (meaning if a customer orders something SMALLER than 3 sq ft they still are charged as if they ordered 3 sq ft, never less - but if they order something larger than 3 sq ft they just pay regularly by the sq ft). What would you charge someone who orders a piece of glass 12in X 12in
Using the same sq ft charge ($5 per sq ft) and remembering the rule about when to use the minimum charge, what would you charge someone ordering a piece of glass 48in X 48in? *
Answer:
12 inches by 12 inches = 15 dollars
48 inches by 48 inches = 80 dollars
Step-by-step explanation:
12 inches = 1 ft
so 12 inch by 12 inches is 1 ft * 1 ft
1 ft* 1 ft
1 ft^2
This is smaller than 3 ft^2 so they will get charged for 3 ft^2
3 ft^2 = 3 ft^2 * $5 / ft^2 = 15 dollars
48 inches = 48/12 = 4 ft
4ft * 4 ft = 16 ft^2
16 ft^2 = 16 ft^2 * $5 / ft^2 = 80 dollars
Jason can peel 15 potatoes in 25 minutes. Janette can peel 8 potatoes in 1/10 hour. If they start peeling at the same time how many
minutes will it take them to peel 406 potatoes?
9514 1404 393
Answer:
210 minutes
Step-by-step explanation:
Jason's rate of peeling is ...
(15 potatoes)/(25 minutes) = 15/25 potatoes/minute = 3/5 potatoes/minute
Janette's rate of peeing potatoes is ...
(8 potatoes)/(6 minutes) = 4/3 potatoes/minute
Their combined rate is ...
(3/5 +4/3) = (9 +20)/15 = 29/15 . . . . potatotes/minute
Then the time required for 406 potatoes is ...
(406 potatoes)/(29/15 potatoes/minute) = (406×15/29) minutes
= 210 minutes
A TV Dinner Company Sells Three Types Of Dinners: A Chicken Dinner For $10, A Beef Dinner For $11, Or A Fish Dinner For $12. At One Particular Grocery Store, They Sold 200 Dinners For A Grand Total Of $2138. Required:a. If they sold three times as many chicken dinners as they did fish, then how many of each kind of dinner did they sell?b. Find the equation of the quadratic function that passes through the points (−1, 9), (2, 6), and (3, 17). Write your answer in the form y = ax2+bx+c.
Answer:
a) The company sold 93 Chicken dinners, 76 Beef dinners and 31 Fish dinners.
b) [tex]y=3x^{2}-4x+2[/tex]
Step-by-step explanation:
a)
In order to solve part a of the problem, we must start by setting our variables up:
C=# of Chicken dinners
B=# of Beef dinners
F=# of Fish dinners
Next we can use these variables to build our equations. We start by taking the fact that they sold a total of 200 dinners. The sum of all the variables should add up to that so we get:
C+B+F=200
Then the problem tells us the price of each dinner and the total amount of money they made from selling the dinners that day:
"A TV Dinner Company Sells Three Types Of Dinners: A Chicken Dinner For $10, A Beef Dinner For $11, Or A Fish Dinner For $12. For A Grand Total Of $2138"
So we can use this information to build our second equation:
10C+11B+12F=2138
We have two equations now but three variables, so we need an additional equation so we can finish solving this. The problem tells us that:
"they sold three times as many chicken dinners as they did fish"
which translates to:
C=3F
so now we have enough information to finish solving the problem. We can start by substituting the last equation into the previous two equations so we get:
C+B+F=200
3F+B+F=200
4F+B=200
and
10C+11B+12F=2138
10(3F)+11B+12F=2138
30F+11B+12F=2138
42F+11B=2138
So now we can take the two bolded equations and solve them simultaneously. We can solve them by using any method we wish. Let's solve it by substitution.
We start by solving the first equation for B so we get:
B=200-4F
and now we substitute it into the second equation:
42F+11(200-4F)=2138
and now we solve for F
42F+11(200-4F)=2138
42F+2200-44F=2138
-2F=2138-2200
[tex]F=\frac{-62}{-2}[/tex]
F=31
So now that we know the value of F, we can find the values of the rest of the variables so we can take the previous equations to figure this out:
B=200-4F
B=200-4(31)
B=200-124
B=76
and finally:
C=3F
C=3(31)
C=93
So
The company sold 93 Chicken dinners, 76 Beef dinners and 31 Fish dinners.
b) For the second part of the problem we need to build a system of equations to find the equation we are looking for. We were given three points:
(-1,9), (2,6) and (3,17)
so we need to substitute each of the points on the given quadratic equation so we get:
[tex]9=a(-1)^{2}+b(-1)+c[/tex]
eq.1: [tex]9=a-b+c[/tex]
[tex]6=a(2)^{2}+b(2)+c[/tex]
eq. 2: [tex]6=4a+2b+c[/tex]
[tex]17=a(3)^{2}+b(3)+c[/tex]
eq. 3: [tex]17=9a+3b+c[/tex]
So now that we have our three equations we can solve them simultaneously to get the values of a, b and c by using the method you feel more comfortable with. Let's solve it by elimination:
So let's take the first equations and let's subtract them:
[tex]9=a-b+c[/tex]
[tex]-6=-4a-2b-c[/tex]
-------------------------------
3=-3a-3b
And now we repeat the process with the first and third equations:
[tex]9=a-b+c[/tex]
[tex]-17=-9a-3b-c[/tex]
-------------------------------
-8=-8a-4b
So now we have two new equations we can solve simultaneously, but they can be simplified by dividing the first one into -3 and the second one into -4 so they become:
a+b=-1
2a+b=2
We can now solve them by substitution. Let's solve the first one for a and then let's substitute it into the second equation:
a=-1-b
let's substitute
2(-1-b)+b=2
and solve for b
-2-2b+b=2
-b=4
b=-4
Now we can find a:
a=-1-b
a=-1+4
a=3
and now we can find c:
c=9-a+b
c=9-3-4
c=2
So we can use these answers to build our equation:
[tex]y=ax^{2}+bx+c[/tex]
[tex]y=3x^{2}-4x+2[/tex]
Solve systems of equations 15 points NOT CLICKBAIT!!! -6y+11y= -36 -4y+7x= -24
Answer:
x = -264/35
y = -36/5
Step-by-step explanation:
-6y + 11y = -36
-4y + 7x = -24
Solve for y in the first equation.
-6y + 11y = -36
Combine like terms.
5y = -36
Divide both sides by 5.
y = -36/5
Plug y as -36/5 in the second equation and solve for x.
-4(-36/5) + 7x = -24
Expand brackets.
144/5 + 7x = -24
Subtract 144/5 from both sides.
7x = -264/5
Divide both sides by 7.
x = -264/35
Answer: -264/35
Step-by-step explanation:
i did my work on a calculator
Find the vector and parametric equations for the line through the point P(0, 0, 5) and orthogonal to the plane −1x+3y−3z=1. Vector Form: r
Answer:
Note that orthogonal to the plane means perpendicular to the plane.
Step-by-step explanation:
-1x+3y-3z=1 can also be written as -1x+3y-3z=0
The direction vector of the plane -1x+3y-3z-1=0 is (-1,3,-3).
Let us find a point on this line for which the vector from this point to (0,0,5) is perpendicular to the given line. The point is x-0,y-0 and z-0 respectively
Therefore, the vector equation is given as:
-1(x-0) + 3(y-0) + -3(z-5) = 0
-x + 3y + (-3z+15) = 0
-x + 3y -3z + 15 = 0
Multiply through by - to get a positive x coordinate to give
x - 3y + 3z - 15 = 0
A circle has center (3, -5) and the point (-1, -8) lies on the circumference of the circle. What is the equation of the circle in Standard Form?
Answer:
[tex] {(x - 3)}^{2} + {(y + 5)}^{2} = {5}^{2} [/tex]
Step-by-step explanation:
First find the radius
Which is the distance between the 2 points.
Radius =5
The answer in the standad form is above.
The equation of the circle in Standard Form is (x - 3)² + (y + 5)² = 25
The standard equation of a circle is given as:
(x - a)² + (y - b)² = r²
where (a, b) is the center of the circle and r is the radius of the circle.
Given the center as (3, -5) hence the radius of the circle is the distance between (3, -5) and (-1, -8). Hence:
[tex]Radius=\sqrt{(-8-(-5))^2+(-1-3)^2} \\\\Radius=5\ units\\[/tex]
hence:
(x - 3)² + (y - (-5))² = 5²
(x - 3)² + (y + 5)² = 25
The equation of the circle in Standard Form is (x - 3)² + (y + 5)² = 25
Find out more at: https://brainly.com/question/13658927
Look at the image for the question.
Answer:
38 cm^2
Step-by-step explanation:
The surface area of a rectangular prism is
SA = 2(lw+wh+lh) where h is the height l is the length and w is the width
SA = 2( 3*1 + 3*4+4*1)
= 2(3+12+4)
= 2(19)
= 38 cm^2
The numbers of words defined on randomly selected pages from a dictionary are shown below. Find the mean, median, mode of the listed numbers. 30 31 64 59 57 33 54 77 56 41 What is the mean? Select the correct choice below and ,if necessary ,fill in the answer box within your choice.(around to one decimal place as needed)
Answer:
30 31 64 59 58 33 54 77 56 41 (arrange it)
30 31 33 41 54 56 58 59 64 77 (done!)
Mean: Find the number in the middle (54+56)/2= 110/2 = 55
Mode: None
Mean: (30+31+33+41+54+56+58+59+64+77)/10=503/10= 50,3
Given the formula A = 5h (B + b); solve for B.
2
Answer:
B = A/5h - b; You could use
B = (A - 5hb)/5h This just puts everything over a common denominator.
Step-by-step explanation:
A = 5h (B + b) Divide both sides by 5h
A/5h = B + b Subtract b from both sides.
A/5h - b = B
Does anyone have the solution to this
Step-by-step explanation:
There is 1 root at x = 1, where the function crosses the x-axis.
There are 2 roots at x = -2, where the function touches the x-axis but does not cross.
So there are 3 real roots total.
The function is:
y = (x − 1) (x − (-2))²
y = (x − 1) (x + 2)²
solve the following system of equations
1/2x+1/4y=-2
-2/3x+1/2y=6
x=
y=
Answer:
x = -6
y = 4
Step-by-step explanation:
Rewriting the equations :
2x + y = -84x - 3y = -36Now, solving the two equations using substitution method, we get :
x = -6
y = 4
Answer:
y = 4
x = -6
Step-by-step explanation:
1/2 x + 1/4 y= -2 first equation
-2/3 x + 1/2 y = 6 second equation
solution:
from the first equation:
8(1/2 x + 1/4 y) = -2*8
8x*1/2 + 8y*1/4 = -16
8x/2 + 8y/4 = -16
4x + 2y = -16 third equation
from the second equation
6(-2/3 x + 1/2 y) = 6*6
6x*-2/3 + 6y*1/2 = 36
-12x/3 + 6y/2 = 36
-4x + 3y = 36 fourth equation
from the third & fourth equation:
4x + 2y = -16
-4x + 3y = 36
0 + 5y = 20
5y = 20
y = 20/5
y = 4
from the fourth equation:
-4x + 3y = 36
-4x + 3*4 = 36
-4x + 12 = 36
-4x = 36 - 12
-4x = 24
x = 24/-4
x = -6
Check:
from the first equation:
1/2 x + 1/4 y = -2
1/2 *-6 + 1/4 * 4 = -2
-3 + 1 0 -2
from the second equation:
-2/3 x + 1/2 y = 6
-2/3 * -6 + 1/2 * 4 = 6
4 + 2 = 6
Consider the age distribution in the United States in the year 2075 (as projected by the Census Bureau). Construct a cumulative frequency plot and describe what information the plot communicates about the distribution of ages in the future.
Answer:
The cumulative frequency plot is also attached below.
Step-by-step explanation:
The data provided is as follows:
Age Group Frequency
0 - 9 34.9
10 - 19 35.7
20 - 29 36.8
30 - 39 38.1
40 - 49 37.8
50 - 59 37.8
60 - 69 34.5
70 - 79 27.2
80 - 89 18.8
90 - 99 7.7
100 - 109 1.7
Consider the Excel output attached.
The cumulative frequency are computed in the Excel sheet.
The cumulative frequency plot is also attached below.
From the cumulative frequency plot it can be seen that in the future most people will belong to a higher age group rather then the lower ones.
Elena drank 3 liters of water yesterday. Jada drank 3/4 times as much water as elena. Link drank twice as much as Jada. Did jada drink more or less then elena? Explain how you know
Answer:
Step-by-step explanation:
3\4 bc on a nuberline it would be 3 3\4
I--I----(etc)
so yeah hope i helped
find the alternateof AHG
Answer:
angle HGD
Step-by-step explanation:
alternate angles are in Z position
Complete the equation describing how
x and y are related.
X
-2
-1
D
у
12
8
0
-8
E 12
y = [? ]x
Enter the answer that belongs in [?]
Answer:
y= -(4x)
Step-by-step explanation:
The art teacher bought 19 sketchbooks for $2.98 per book. What equation can be used to find the total cost of the sketchbooks?
Answer:
y = 2.98x
Step-by-step explanation:
x = number of sketchbooks
y = total cost
The data represents the daily rainfall (in inches) for one month. Construct a frequency distribution beginning with a lower class limit of and use a class width of . Does the frequency distribution appear to be roughly a normal distribution?
Answer:
The frequency distribution does not appear to be normal.
Step-by-step explanation:
The data provided is as follows:
S = {0.38 , 0 , 0.22 , 0.06 , 0 , 0 , 0.21 , 0 , 0.53 , 0.18 , 0 , 0 , 0.02 , 0 , 0 , 0.24 , 0 , 0 , 0.01 , 0 , 0 , 1.28 , 0.24 , 0 , 0.19 , 0.53 , 0 , 0, 0.24 , 0}
It is provided that the first lower class limit should be 0.00 and the class width should be 0.20.
The frequency distribution table is as follows:
Class Interval Count
0.00 - 0.19 21
0.20 - 0.39 6
0.40 - 0.59 2
0.60 - 0.79 0
0.80 - 0.99 0
1.00 - 1 . 19 0
1.20 - 1. 39 1
The frequency distribution does not appear to be normal. This is because the frequencies does not start and end at almost equivalent points and the mid-distribution does not consist of the highest frequency.
Thus, the frequency distribution does not appear to be normal.
A semicircular plate with radius 7 m is submerged vertically in water so that the top is 3 m above the surface. Express the hydrostatic force against one side of the plate as an integral and evaluate it. (Round your answer to the nearest whole number. Use 9.8 m/s2 for the acceleration due to gravity. Recall that the weight density of water is 1000 kg/m3.)
Answer:
F = 585844 N
Step-by-step explanation:
Given that:
A semicircular plate with radius 7 m is submerged vertically in water so that the top is 3 m above the surface.
The objective of this question is to express the hydrostatic force against one side of the plate as an integral and evaluate it.
To start with the equation of a circle: a² + b² = r²
The equation of circle with radius r = 7 can be expressed as:
a² + b² = 7²
a² + b² = 49
b² = 49 - a²
b = [tex]\sqrt{49 -a}[/tex]
NOW;
The integral of the hydrostatic force with a semicircular plate with radius 7 m and the top is 3 m above the surface can be calculated as follows:
[tex]\mathtt{F = 2 \rho g \int \limits^7_3 (a -3) \sqrt{49 -y^2} \ \ da}[/tex]
[tex]\mathtt{F = 2 \rho g \begin {pmatrix}\dfrac{\sqrt{49 -a^2} \ (2a^2-9a - 98)-(441 \times sin^{-1} (\dfrac{a}{3})) }{6} \end{pmatrix}}[/tex]
where;
density of water is 1000 kg/m3
and acceleration due to gravity is 9.8 m/s
Solving the integral; we have:
F = 2 × 1000 kg/m³ × 9.8 m/s × (29.89)
F = 585844 N
Jerry was given some birthday money He puts the money in an account Every month after that he deposits the same amount of money The equation that models this situation y=50x+75 where y is the amount of money int he account and x is the number of deposits What does the y- intercept means in this situation
Answer: He was given $75 for his birthday
Step-by-step explanation:
The y - intercept represents the rate of which the money is being deposited in the account.
What is linear equation in two variable ?"An equation is said to be linear equation in two variables if it is written in the form of ax + by + c=0, where a, b & c are real numbers and the coefficients of x and y, i.e a and b respectively, are not equal to zero."
"The solution of linear equations in two variables, ax+by = c, is a particular point in the graph, such that when x-coordinate is multiplied by a and y-coordinate is multiplied by b, then the sum of these two values will be equal to c.
Basically, for linear equation in two variables, there are infinitely many solutions."
The given equation is y = 50x + 75
The y intercept represents the amount of money to be deposited in account. The rate of change of money in the account with represent to the months.
Hence, y represents money deposited in the account.
To know more about linear equation in two variable here
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Roll a dice six times. Find the probability that :
a . The back of the dot appears exactly 4 times ;
Answer:
2/3???
.................
Answer:
0.804% to 3 dec places.
Step-by-step explanation:
If the first 4 throws are a dot and the next 2 are not:
Probability = (1/6)^4 * (5/6)^2
= 25/46656
There are 6C4 ways for this to happen
6C4 = (6*5*4*3)/ (4*3*2*1) = 15 ways.
So The required probability = (25*15)/46656
= 125/15552
= 0.00804
= 0.804%
urgent !!!!!!!!!!!!!!! 10 points
Answer:
136 cm²
Step-by-step explanation:
Surface area = 2(lw+wh+hl)
l = 7
w = 2
h = 6
so,
2(7×2+2×6+7×6)
= 136 cm²
Answer:
136 cm^2
Step-by-step explanation:
L 7cm
W 6cm
D 2cm
7 x 6 + 6 x 2 + 2 x 7 (x 2) = 68 x 2 = 136cm^2
which decimal is equivalent to 6×100+7×10+4×1/10+8×1/1,000
The answer is 670.408, because 6x100=600, 7x10=70, 4x1/10 as a decimal is 0.4, 8x1/1,000 as a decimal is 0.008. Then, you add all of those [tex]600+70+0.4+0.008=670.408[/tex].
suppose a chemical engineer randomly selects 3 catalysts for testing from a group of 10 catalysts, 6 of which have low acidity & 4 have high acidity. What is the probability that exactly2 lower acidic catalysts are selected?
Step-by-step explanation:
Total catalysts = 10
Probability of 2 lower acidic catalysts = 2/10 = 1/5
Carmen Martinez
What is the slope of the line that passes through the point 4,4 and 10,7 write your answer in simplest form
[tex]\boxed{\sf Slope(m)=\dfrac{y_2-y_1}{x_2-x_1}}[/tex]
[tex]\\ \sf\longmapsto m=\dfrac{7-4}{10-4}[/tex]
[tex]\\ \sf\longmapsto m=\dfrac{3}{6}[/tex]
[tex]\\ \sf\longmapsto m=\dfrac{1}{2}[/tex]
[tex]\\ \sf\longmapsto m\approx0.5[/tex]
Answer:
[tex]m=\frac{1}{2}[/tex]
Step-by-step explanation:
The slope of a line, also known as the change in the line or the ([tex]\frac{rise}{run}[/tex]) can be found using the following formula,
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]
Where ([tex]x_1,y_1[/tex]) and ([tex]x_2,y_2[/tex]) are points on the line. Substitute the given information into the formula and solve for the slope.
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]
Points on the line: [tex](4,4)\ \ \ (10, 7)[/tex]
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]
[tex]m=\frac{7-4}{10-4}[/tex]
[tex]m=\frac{3}{6}[/tex]
[tex]m=\frac{1}{2}[/tex]
[tex]m=0.5[/tex]
Maria operates a taco truck in her neighborhood. She has created a graph based on her business performance in the previous year. The price she currently sells tacos for is $2.30. Which two statements correctly interpret this graph? Revenue and Cost Functions 1)Maria’s business is incurring losses. 2)Maria’s costs are rising over time. 3)Maria is running a profitable business. 4)Maria’s total revenue exceeds her total profit. 5)Maria’s total profit exceeds her total revenue.
Answer:
3)Maria is running a profitable business.
4)Maria’s total revenue exceeds her total profit.
Step-by-step explanation:
The graph shows variation of revenue and cost with respect to price of product and not with respect to time .
The price of the product is 2.30 . From this graph , we see that at this price revenue exceeds total cost . So maria is running a profitable business .
Total profit can not exceed total revenue as
Total revenue - total cost = total profit .
So total profit will always be less than total revenue .
A number plus its fifth add up to 17 What is the number
Answer:
Step-by-step explanation:
we call the number X
x/5 is the fifth part of that number
I propose equality:
x + x/5 = 17
we add the fractions on the left side:
6x/5 = 17
We pass 5 to multiply to the other side:
6x = 5 * 17
6x = 85
we clear x
x = 85/6
x = 14.17
test
14.17 + 2.83 = 17
okay
Answer:
14.1666666667
Step-by-step explanation:
We can write the equation as:
x + x/5 = 17
=> 5/5x + 1/5x = 17
=> 6/5x = 17
=> 6x = 17 * 5
=> 6x = 85
=> x = 85/6
=> x = 14.1666666667
Let's check whether our answer is correct
=> 14.1666666667 + 14.1666666667 / 5 = 17
=> 14.1666666667 + 2.83333333333 = 17
=> 17 = 17
So, the answer is 14.1666666667
Suppose that three computer boards in a production run of forty are defective. A sample of five is to be selected to be checked for defects.
a. How many different samples can be chosen?
b. How many samples will contain at least one defective board?
c. What is the probability that a randomly chosen sample of five contains at least one defective board?
Answer:
(a) 658,008 different samples can be chosen.
(b) 222,111 samples will contain at least one defective board.
(c) The probability that a randomly chosen sample of five contains at least one defective board is 0.34.
Step-by-step explanation:
We are given that three computer boards in a production run of forty are defective. A sample of five is to be selected to be checked for defects.
(a) To find how many different samples can be chosen, we will use a combination formula here because the order of selecting a sample of 5 from the production run of 40 doesn't matter.
Here, n = total sample = 40 and r = selected sample = 5
So, the combination formula is; [tex]^{n}C_r= \frac{n!}{r! \times (n-r)!}[/tex]
[tex]^{40}C_5= \frac{40!}{5! \times (40-5)!}[/tex]
[tex]^{40}C_5= \frac{40!}{5! \times 35!}[/tex]
[tex]^{40}C_5[/tex] = 658,008 ways
So, 658,008 different samples can be chosen.
(b) To find how many samples will contain at least one defective board, we will first find how many samples will contain no or 0 defective board.
For this also, we will use a combination where n = 40 - 3 = 37 non-defective computer board and a sample of r = 5 computer boards.
So, [tex]^{n}C_r= \frac{n!}{r! \times (n-r)!}[/tex]
[tex]^{37}C_5= \frac{37!}{5! \times (37-5)!}[/tex]
[tex]^{37}C_5= \frac{37!}{5! \times 32!}[/tex]
[tex]^{37}C_5[/tex] = 435,897 ways
This means that 435,897 of the 658,008 samples will contain no defective board.
Now, the samples that will contain at least one defective board = Total samples - Samples that contain no defective board
= 658,008- 435, 897
= 222,111
(c) The probability that a randomly chosen sample of five contains at least one defective board is given by;
Required Probability = [tex]\frac{222,111}{658,008}[/tex]
= 0.34 or 34%
A schoolteacher would like to know whether or not toothpaste brands are used differentially in her classroom (in other words, is one brand preferred over the others?). She asks her students to report which of three brands they use: Crest, Colgate, or Aquafresh. Below are the numbers of students who use each type of toothpaste (notice there are 45 students total in her class). Test her hypothesis using an alpha level of .05.
Crest Colgate Aquafresh
24 13 8
a. What test is appropriate for this analysis?
b. State the null hypothesis:
c. State the alternative hypothesis:
d. Find the critical value:
e. Calculate the test statistic:
f. Make a decision:
Answer:
Step-by-step explanation:
a. What test is appropriate for this analysis?
A Chi-square test of independence is appropriate for this analysis because it is used to compare two variables or testing relationship on categorical variables.
b. State the null hypothesis:
The null hypothesis is the default hypothesis
[tex]\mathtt{H_o:}[/tex] There is no particular preference for any brand of toothpaste among students.
c. State the alternative hypothesis:
The alternative hypothesis is the research hypothesis which comes in place to challenge the validity of the null hypothesis.
[tex]\mathtt{H_a:}[/tex] There is particular preference for brands of toothpaste among students.
d. Find the critical value:
degree of freedom = n-1
degree of freedom = 3 - 1
degree of freedom = 2
At the level of significance ∝ = 0.05
The confidence interval = 0.95 and degree of freedom = 2, the critical value from the chi-square distribution table = 5.991
e. Calculate the test statistic:
Using the chi square test statistics; we have the following:
Crest Colgate Aquafresh Total
24 13 8 45
Since we have three brands. Then, for each brand, the expected value
= Total /3
= 45/3
=15
Thus:
Chi -square [tex]\mathtt{X^2 = \dfrac{(observed \ value - expected \ value)^2}{expected \ value}}[/tex]
[tex]\mathtt{X^2 = \dfrac{(24 - 15)^2}{15} + \dfrac{(13 - 15)^2}{15} + \dfrac{(8 - 15)^2}{15} }[/tex]
[tex]\mathtt{X^2 = \dfrac{81}{15} + \dfrac{4}{15} + \dfrac{49}{15} }[/tex]
[tex]\mathtt{X^2 = \dfrac{81+4+49}{15}}[/tex]
[tex]\mathtt{X^2 = \dfrac{134}{15}}[/tex]
[tex]\mathtt{X^2 =8.93 }[/tex]
f. Make a decision:
Since the chi-square value is greater than the critical value , we reject the null hypothesis and conclude that the students have particular preference for brands of toothpaste.
the temperature at which water freezes on the celsius scale is 0 degrees C. It freezes at 32 degrees F on the Fahrenheit scale, write opposites fo these two numbers as integers.
Answer:
If we have an integer number N, the opposite of N will be:
-1*N = -N.
Then, the opposite of 0°C is:
-1*0°C = 0°C.
The number 0 is it's own opposite.
And for 32F, the opposite is:
-1*32F = -32F
So, while the numbers 0°C and 32F physically represent the same thing (the same temperature), mathematically, they behave differently.
* 2. Use digits and other symbols to write "One hundred one thousand is
greater than one thousand, one hundred."
Answer:
101,000>1,100
Step-by-step explanation:
101,000>1,100
Answer:
101,000>1,100
Step-by-step explanation: