[tex]S_n=\dfrac{n(a_1+a_n)}{2}\\a_1=200\\a_n=1998\\n=?\\\\a_n=a_1+(n-1)d\\d=2\\1998=200+(n-1)\cdot2\\2n-2=1798\\2n=1800\\n=900\\\\S_{900}=\dfrac{900\cdot(200+1998)}{2}=450\cdot 2198=989100[/tex]
The Sum is 989100.
what is sum of Even numbers?The sum of even numbers formula is determined by using the formula to find the arithmetic progression. The sum of even numbers goes on until infinity. The sum of even numbers formula can also be evaluated using the sum of natural numbers formula. We need to obtain the formula for 2 + 4+ 6+ 8+ 10 +...... 2n.
The sum of even numbers = 2(1 + 2+ 3+ .....n). This implies 2(sum of n natural numbers) = 2[n(n+1)]/2 = n(n+1)
Given:
a1 = 200
an= 1998
So, using formula
S= n(a1 + an)/2
now,
d=2
an= a1+(n-1)d
1998= 200 + (n-1) 2
1998-200= (n-1)2
1798/2=n-1
n= 900
S900= 900( 200 + 1998)/2
=450*2198
= 989100
Hence, the sum is 989100.
Learn more about this concept here:
https://brainly.com/question/18837188
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Open the graphing tool. Move the slider for the equation y = kx3 to a position of your choice, where k ≠ 1. Next, move the slider of y = (kx)3 so the two graphs lie on top of one another. How do the values of k compare with one another in this situation? Why do you think that is?
Answer:
For the functions to coincide, the value of k in y = (kx)3 must be smaller than in y = kx3. This is because the value of y changes more rapidly when k is cubed inside the parentheses. The behavior of the functions is similar since a vertical stretch is similar to a horizontal compression.
Step-by-step explanation:
PLATO
(math and social studies) The two lines are messing me up and I'm not sure
Answer:
2009
Step-by-step explanation:
A deficit would be the least amount coming in (Revenues). and the most going out (Expenditures). So you look for the biggest gap. It appears the gap is largest in 2009.
A right circular cone has a volume of 30π m. If the height of the cone is multiplied by 6 but the radius remains fixed, which expression represents the resulting volume of the larger cone?
A. 6 + 30π m
B. 6 x 30π m
C. 6 x 30π m
D. 6 x (30π) m
PLZ HURRY IM TIMED
Answer:
Below
Step-by-step explanation:
The formula of the volule of a cone is:
● V= (1/3) × Pi × r^2 × h
h is the height and r is the radius.
■■■■■■■■■■■■■■■■■■■■■■■■■■
We are given that the volume is 30 Pi m^3
● V = 30 Pi
● 1/3 × Pi × r^2 × h = 30 Pi
If we multiply h by 6 we should do the same for 30 Pi since it's an equation
● 1/3 × Pi × r^2 × h = 30 × Pi × 6
Answer:
REVIEW: B is Correct Exit
A right circular cone has a volume of 30π m. If the height of the cone is multiplied by 6 but the radius remains fixed, which expression represents the resulting volume of the larger cone?
A. 6 + 30π m
B. 6 x 30π m
C. 6 x 30π m
D. 6 x (30π) m
Step-by-step explanation:
The answer is be all i did was dig into what the other person was saying and got b it is correct:)
Suppose the following data show the prices of 4 cars with similar characteristics that sold at a recent auction (in thousands of dollars): 6.6, 5, 10.7, 7.3. Calculate the standard deviation of the sample of selling prices. (please express your answer using 2 decimal places)
Answer: 2.40
Step-by-step explanation:
Given: The prices of 4 cars with similar characteristics that sold at a recent auction (in thousands of dollars): 6.6, 5, 10.7, 7.3.
Let x: 6.6, 5, 10.7, 7.3.
n= 4
Mean : [tex]\overline{x}=\dfrac{\sum x}{n}[/tex]
[tex]\Rightarrow\ \overline{x}=\dfrac{6.6+5+10.7+7.3}{4}\\\\=\dfrac{29.6}{4}\\\\=7.4[/tex]
Now , standard deviation = [tex]\sqrt{\dfrac{\sum(x-\overline{x})^2}{n-1}}[/tex]
[tex]=\sqrt{\dfrac{(6.6-7.4)^2+( 5-7.4)^2+( 10.7-7.4)^2+( 7.3-7.4)^2}{4-1}}\\\\=\sqrt{\dfrac{0.64+5.76+10.89+0.01}{3}}\\\\=\sqrt{\dfrac{17.3}{3}}\approx2.40[/tex]
Hence, the standard deviation of the sample of selling prices = 2.40
A box of colored crayons contains 11 distinct colors. In how many ways can 2 colors be chosen, assuming that the order of the colors chosen doesn’t matter? (If necessary consult a list of formulas.)
Answer:
55
Step-by-step explanation:
The first crayon is chosen out of 11,so there are 11 choices
11
The second crayon is chosen out of 10 crayons left so there are 10 choices
10
11*10 = 110
But we do not care about the order, so we divide by 2 since there are 2 places
110/2 =55
Answer:
55
Step-by-step explanation:
Equation is a = n * (n-1)
11 * 10 = 110
Order doesn't matter, and two colors, so divide by 2.
110/2 = 55
Which option is correct and how would one solve for it?
Answer:
102
Step-by-step explanation:
We have the sum for k = 1 to 4 of 3 ^ ( k-1) * ( k-1)
k =1 3 ^ (1-1) * ( 1-1) = 3^0 * 0 = 0
k =2 3 ^ (2-1) * ( 2-1) = 3^1 * 1 = 3
k =3 3 ^ (3-1) * ( 3-1) = 3^2 * 2 = 9*2 = 18
k =4 3 ^ (4-1) * ( 4-1) = 3^3 * 3 = 27 *3 = 81
Add these together
0+3+18+81 =102
━━━━━━━☆☆━━━━━━━
▹ Answer
102
▹ Step-by-Step Explanation
Convert the notation into a sum and substitute values from 1-4:
(3¹⁻¹ *(1 - 1)) + (3²⁻¹ * (2 - 1)) + (3³⁻¹ * (3 - 1)) + (3⁴⁻¹ * (4 - 1))
0 + 3 + 18 + 81
= 102
Hope this helps!
CloutAnswers ❁
━━━━━━━☆☆━━━━━━━
HELP PLEASE PLEASE :(
Answer:
16
Step-by-step explanation:
It’s a ratio.
x/12=21/28
21x=12*28
21x=336
x=336/21
x=16
The expression $16x^2-106x-105$ can be written as $(8x + a)(2x + b),$ where $a$ and $b$ are integers. What is $a + 2b$?
Answer:
-23
Step-by-step explanation:
16x² - 106x - 105
factoring X
14 x -120 = -1680
14 - 120 = -106
16x² + 14x - 120x - 105
(16x² + 14x) -(120x - 105)
factor out 2 and -15 to get the same expression (8x + 7)
2x(8x + 7) - 15(8x + 7)
(8x + 7)(2x - 15)
a = 7
b = -15
a + 2b
7 + (-15 x 2)
7 + (-30)
= -23
2. A 10 Mg truck hauls a 20 Mg trailer. If the unit starts from rest on a level road with a
tractive force of 20 kN between the driving wheels of the truck and the road, calculate the
acceleration of the unit and the tension in the horizontal draw-bar.
Drawbar
20 Mg Trailer
10 Mg Truck
a=0.667 m/s2
T= 13.3 KN
Oro
W
Answer:
The acceleration on the unit is 0.667 m/s^2
The tension on the draw-bar is 13.34 kN
Step-by-step explanation:
The mass of the truck = 10 Mg = 10 x 10^3 kg
The mass of the trailer = 20 Mg = 20 x 10^3 kg
Tractive force from the truck = 20 kN = 20 x 10^3 N
The total mass of the unit = 10 Mg + 20 Mg = 30 Mg = 30 x 10^3 kg
The tractive force on the unit will produce an acceleration that is given as
F = ma
where
F is the tractive = 20 x 10^3 N
m is the mass of the unit = 30 x 10^3 kg
a is the acceleration of the unit = ?
substituting into the equation
20 x 10^3 = 30 x 10^3 x a
a = (20 x 10^3)/(30 x 10^3) = 0.667 m/s^2
the tension on the draw-bar T is gotten from considering only the mass that is pulled by the draw-bar which is 20 Mg
The acceleration on the unit = 0.667 m/s^2
The drawn mass = 20 Mg = 20 x 10^3 kg
The tension on the draw bar = ma = 20 x 10^3 x 0.667 = 13340 N
= 13.34 kN
The acceleration is 0.00067m/s^2, while the tension on the horizontal bar is 13.4 N
The given parameters are:
[tex]\mathbf{m = 10Mg}[/tex] -- mass of the truck
[tex]\mathbf{M = 20Mg}[/tex] -- mass of the trailer
[tex]\mathbf{F_T = 20kN}[/tex] --- tractive force
Start by calculating the total mass
[tex]\mathbf{M_T = m + M}[/tex]
So, we have:
[tex]\mathbf{M_T = 10Mg + 20Mg}[/tex]
[tex]\mathbf{M_T = 30Mg}[/tex]
Convert to kilograms
[tex]\mathbf{M_T = 30 \times 10^3kg}[/tex]
[tex]\mathbf{M_T = 30000 kg}[/tex]
Force is calculated as:
[tex]\mathbf{F =ma}[/tex]
So, we have:
[tex]\mathbf{20kN =30000kg \times a}[/tex]
Divide both sides by 30000
[tex]\mathbf{a = 0.00067ms^{-2}}[/tex]
The tension on the horizontal bar (i.e. the 20 Mg trailer) is:
[tex]\mathbf{T=ma}[/tex]
So, we have:
[tex]\mathbf{T=20Mg \times 0.00067ms^{-2}}[/tex]
Rewrite as:
[tex]\mathbf{T=20 \times 10^3 kg \times 0.00067m/s}[/tex]
[tex]\mathbf{T=13.4N}[/tex]
Hence, the acceleration is 0.00067m/s^2, while the tension on the horizontal bar is 13.4 N
Read more about force and acceleration at:
https://brainly.com/question/20511022
Solve for X: 1+1*12/80-2+3=56x
Answer:
NOT SURE
Step-by-step explanation:
Help! Solve equation: xe^2x=0
Answer: x=0
Step-by-step explanation:
For this problem, there are no calculations needed. You just have to know your algebraic properties. Since we are looking for x, we know that x must be 0. The answer is 0. Figuring out e²ˣ can be tricky, but since there is an x multiplying it in front, we know that x must be 0 to make the equation equal to 0.
The U.S. National Whitewater Center in Charlotte uses a pump station to provide the flow of water necessary to operate the rapids. The pump station contains 7 pumps, each with a capacity to deliver 80,000 gallons per minute (gpm). The water channels and ponds in the facility contain 13 million gallons of water. If the pump station is operating 5 pumps simultaneously, assuming ideal conditions how long will it take to completely pump the volume of the system through the pump station
Answer:
t = 32,5 minutes
Step-by-step explanation:
Volume to fill = 13000000 Gal
5 pumps delivering 80000 gal/min
5 * 80000 = 400000 gal/min
If we divide the total volume by the amount of water delivered for the 5 pumps, we get the required time to fill the volume, then
t = 13000000/ 400000
t = 32,5 minutes
How many odd numbers with 4 different digits, can be formed using the digits 1, 2, 3, 4, 5, 6, 7, 8? (No repetition is allowed)
A. 71
B. 200
C. 210
D. 840
E.1680
Answer:
840 ( D )
Step-by-step explanation:
GIVEN DIGITS : 1,2,3,4,5,6,7,8
Number of odd numbers = 4
Number of even numbers = 4
therefore the number of odd numbers with 4 different digits can be formed by the same way the number of even numbers ( without repetition )
Hence the number of ways odd numbers with 4 different digits = Total number of ways of forming 4 digit numbers / 2
8*7*6*5 = 1680 / 2 = 840 ways
Assume a significance level of alpha = 0.05 and use the given information to complete parts (a) and (b) below. Original claim: The standard deviation of pulse rates of a certain group of adult males is more than 11 bpm. The hypothesis test results in aP-value of 0.2761.a. State a conclusion about the null hypothesis.(Reject H0 or fail to reject H0.) Choose the correct answer below.A. Fail to reject H0 because the P-value is less than or equal to alphaα.B. Reject H0 because the P-value is less than or equal to alphaα.C.Fail to reject H0 because the P-value is greater than alphaα.D. Reject H0 because the P-value is greater than alphaα.b. Without using technical terms, state a final conclusion that addresses the original claim. Which of the following is the correct conclusion?A. The standard deviation of pulse rates of the group of adult males is more than 11 bpm.B. There is not sufficient evidence to support the claim that the standard deviation of pulse rates of the group of adult males is more than 11 bpm.C. The standard deviation of pulse rates of the group of adult males is less than or equal to 11 bpm.D. There is sufficient evidence to support the claim that the standard deviation of pulse rates of the group of adult males is more than 11 bpm.
Answer:
a
The correct option is B
b
The correct option is D
Step-by-step explanation:
From the question we are told that
The level of significance is [tex]\alpha = 0.05[/tex]
The p-value is [tex]p = 0.2761[/tex]
Considering question b
Given that the [tex]p< \alpha[/tex] then the null hypothesis is rejected
Considering question b
Given that the original claim is The standard deviation of pulse rates of a certain group of adult males is more than 11 bpm
Then the null hypothesis is [tex]H_o : \sigma = 11[/tex]
The reason why the null hypothesis is write like this above is because a null hypothesis expression can not contain only a > or a < but only allows = [tex]\le , \ and \ \ge[/tex]
and the alternative hypothesis is [tex]H_a : \sigma > 11[/tex]
Now given that the null hypothesis is rejected, it mean that there is sufficient evidence to support original claim
Consider a bag of jelly beans that has 30 red, 30 blue, and 30 green jelly beans. a) How many color combinations of 15 beans have at least 6 green beans
Answer:
680
Step-by-step explanation:
Number of red beans = 30
Number of Blue beans = 30
Number of green beans = 30
How many color combinations of 15 beans have at least 6 green beans?
Since at least 6 of the beans must be green,
Then (15 - 6) = 9
Then, the remaining 9 could be either red, blue or green.
Therefore, C(9 + (9 - 1), 3)
C(17, 3) = 17C3
nCr = n! ÷ (n-r)! r!
17C3 = 17! ÷ (17 - 3)! 3!
17C3 = 17! ÷ 14!3!
17C3 = (17 * 16 * 15) / (3 * 2)
17C3 = 4080 / 6
17C3 = 680 ways
Using the combination formula, it is found that there are 17,157,323,000,000,000 color combinations of 15 beans have at least 6 green beans.
The order in which the beans are chosen is not important, hence, the combination formula is used to solve this question.
Combination formula:
[tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by:
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
Th total number of combinations of 15 beans from a set of 30 + 30 + 30 = 90 is:
[tex]C_{90,15} = \frac{90!}{15!75!} = 45795674000000000[/tex]
With less than 6 green, we have:
0 green:
[tex]C_{30,0}C_{60,15} = \frac{60!}{15!45!} = 53194089000000[/tex]
1 green:
[tex]C_{30,1}C_{60,14} = \frac{30!}{1!29!} \times \frac{60!}{14!46!} = 520376960000000[/tex]
2 green:
[tex]C_{30,2}C_{60,13} = \frac{30!}{2!28!} \times \frac{60!}{13!47!} = 2247585600000000[/tex]
3 green:
[tex]C_{30,3}C_{60,12} = \frac{30!}{3!27!} \times \frac{60!}{12!48!} = 5681396900000000[/tex]
4 green:
[tex]C_{30,4}C_{60,11} = \frac{30!}{4!26!} \times \frac{60!}{11!49!} = 9391696900000000[/tex]
5 green:
[tex]C_{30,5}C_{60,10} = \frac{30!}{5!25!} \times \frac{60!}{10!50!} = 10744101000000000[/tex]
Hence, the total for the number of combinations with less than 5 green is:
[tex]53194089000000 + 520376960000000 + 2247585600000000 + 5681396900000000 + 9391696900000000 + 10744101000000000 = 28638351000000000[/tex]
Subtracting the total amount of combinations from the number with less than 5 green, the number of combinations with at least 6 green is:
[tex]T = 45795674000000000 - 28638351000000000 = 17157323000000000[/tex]
There are 17,157,323,000,000,000 color combinations of 15 beans have at least 6 green beans.
A similar problem is given at https://brainly.com/question/24437717
How many solutions does the following equation have?
-5(z+1)=-2z+10
Choose 1 answer:
A: No solutions
B: Exactly one solution
C: Infinitely many solutions
Answer:
B
Step-by-step explanation:
-5z +1 = -2z +10
-3z = 9
z=9/-3
Z= -3
Answer:
the answer is exactly one solution
Step-by-step explanation:
this is the answer because i just took this question on khan academy and the one solution is z = -5 for the equation
which function's graph has asymphotes located at the values x=+=n pi ? 1. y=csc x 2. y= cos x 3. y=tan x 4. y=cot x answer choices: A. 2 only B. 1 and 4 only C. 1 only D. 1 and 3 only please help!! ):
Find the radius of the circle with equation x^2 + y^2 - 10x - 16y + 53 = 0.
Answer:
radius = 10.5 unitsStep-by-step explanation:
Equation of a circle is given by
x² + y² + 2gx + 2fy + c = 0
To find the radius of the circle we use the formula
[tex]r = \sqrt{ {g}^{2} + {f}^{2} - c } [/tex]
where g and f is the center of the circle
From the question
x² + y² - 10x - 16y + 53 = 0
Comparing with the general equation above we have
2g = - 10 2f = - 16
g = - 5 f = - 8
c = 53
Substitute the values into the above formula
That's
[tex]r = \sqrt{ ({ - 10})^{2} + ( { - 8})^{2} - 53 } [/tex]
[tex]r = \sqrt{100 + 64 - 53} [/tex]
[tex]r = \sqrt{111} [/tex]
We have the final answer as
radius = 10.5 unitsHope this helps you
find the domain of the graphed function.
Kelvin wants to know whether he skied without falling more than twice as long as anyone else in his family. His dad tells him that he can check by using the inequality 2f < 223, where f is the time skied in seconds for each person. Plug the values for the time skied by each person into the inequality to find the answer.
Lori 55
Vanessa 265
Devon 172
Celia 112
Arnold 356
Answer:
Kelvin did not skied without falling more than twice as long as anyone else in his family.
Step-by-step explanation:
The inequality representing the event where Kelvin skied without falling more than twice as long as anyone else in his family is:
[tex]2f<223[/tex]
Here 223 is the time for Kelvin.
Check for Lori as follows:[tex]2f<223[/tex]
[tex]2\times 55=110<223[/tex]
Kelvin skied without falling more than twice as long as Lori.
Check for Vanessa as follows:[tex]2f<223[/tex]
[tex]2\times 265=530>223[/tex]
Kelvin skied without falling less than twice as long as Vanessa.
Check for Devon as follows:[tex]2f<223[/tex]
[tex]2\times 172=344>223[/tex]
Kelvin skied without falling less than twice as long as Devon.
Check for Celia as follows:[tex]2f<223[/tex]
[tex]2\times 112=224>223[/tex]
Kelvin skied without falling less than twice as long as Celia.
Check for Arnold as follows:[tex]2f<223[/tex]
[tex]2\times 356=712>223[/tex]
Kelvin skied without falling less than twice as long as Arnold.
Thus, Kelvin did not skied without falling more than twice as long as anyone else in his family.
Answer:
Yes, Kevin skied 2x as long as Lori.
Step-by-step explanation:
Kevin's time was 223 seconds; Lori's time was 110 seconds.
110^2 = 220 or 110 multiplied by 2 equals 220 or 110 x 2 = 220 or
110 * 2 = 220
Thus, Kevin indeed, skied twice as long as Lori.
4.9x10^_8 In decimal notation
Answer:
490000000
Step-by-step explanation:
For every exponent of 10, move the decimal point one place to the right.
State the correct polar coordinate for the graph shown:
Answer:
Solution : ( - 5, 5π / 4 )
Step-by-step explanation:
There are four cases to consider here, the first two with respect to r > 0, the second two with respect to r < 0. r is the directed distance from the pole, and theta is the directed angle from the positive x - axis. Let's start by listing coordinates when r is positive. r here is 5 units from the positive x - axis.
( 5, θ ) theta here is between 30 and 60 degrees, so we can say it's about 45 degrees.
( 5, θ ) theta here is the remaining negative side of 360 - 45 = 315. That would make it - 315.
And when r is negative ( r < 0 ),
( - 5, θ ) now the point is going to lie on the ray pointing in the opposite direction of the terminal side of theta. This will be 45 degrees more than 180, or 180 + 45 = 225 degrees.
Right away we know that ( - 5, 225° ) is our solution, we don't have to consider the second case. Converting 225 to radians in terms of π will be 5π / 4 radians, giving us a solution of ( - 5, 5π / 4 ) or option b.
Question
Consider this expression.
4/2² - 6²
Type the correct answer in the box. Use numerals instead of words. For help, see this worked example e.
When a =
-5 and b = 3, the value of the expression is
Submit
Answer:
16
Step-by-step explanation:
4 * sqrt( a^2 - b^2)
Let a = -5 and b =3
4 * sqrt( (-5)^2 - 3^2)
Do the squaring first
4 * sqrt( 25 - 9)
Subtract inside the square root
4 * sqrt( 16)
Take the square root
4 * 4
Multiply 16
Answer:
[tex]\Large \boxed{16}[/tex]
Step-by-step explanation:
[tex]4\sqrt{a^2-b^2 }[/tex]
[tex]\sf Plug \ in \ the \ values \ for \ a \ and \ b.[/tex]
[tex]4\sqrt{-5^2-3^2 }[/tex]
[tex]4\sqrt{25-9 }[/tex]
[tex]4\sqrt{16}[/tex]
[tex]4 \times 4=16[/tex]
which expression is equivalent to(x²y)³?
Answer:
x^6 y^3
Step-by-step explanation:
(x²y)³
We know that (ab) ^c = a^c * b^c
(x²y)³ = x^2 ^3 * y^3
We know that a^b^c = a^(b*c)
(x²y)³ = x^2 ^3 * y^3 = x^( 2*3) y^3 = x^6 y^3
This person did something wrong and I do not know what it is :( Please help this is for points!
Answer:
0.4 cm
Step-by-step explanation:
The magnifying glass basically zooms into smaller objects. If the insect appears to be 2cm, then it is actually smaller than this. It cannot be 10 cm.
If the scale factor is 5, then this means that the insect is zoomed in 5 times through the magnifying glass. Use the following ratio:
[tex]\frac{2}{5}[/tex]
This fraction can also be seen as division, so:
[tex]2[/tex]÷[tex]5=0.4[/tex]
The insect is actually 0.4 cm long.
(or 4 millimeters)
:Done
If f(x)=4x-6 and g(x) vx+2 what is (f*g)(7)
Answer: The value of (f*g)(7) is 66.
Step-by-step explanation:
Given functions: [tex]f(x)= 4x-6\text{ and } g(x)=\sqrt{x+2}[/tex]
Since, product of two functions: [tex](u*v)(x)=u(x)\times v(x)[/tex]
[tex](f*g)(x)=f(x)\times g(x)\\\\=4x-6\times \sqrt{x+2}\\\\\Rightarrow\ (f*g)(x)=(4x-6) \sqrt{x+2}[/tex]
[tex](f*g)(7)=(4(7)-6)\sqrt{7+2}\\\\=(28-6)\sqrt{9}\\\\=22\times 3=66[/tex]
Hence, the value of (f*g)(7) is 66.
4. Katy has 6 times as many nickels as
Shaun. Shaun has 18 nickels. How many
nickels, n, does Katy have?
n is 6
18.
n=
Answer:
[tex]\huge\boxed{n = 108\ nickels}[/tex]
Step-by-step explanation:
Let the nickels with Katy be n
So, the condition is
n = 6 (Shaun nickels)
While Nickels of Shaun = 18 , So
n = 6 (18)
n = 108 nickels
If AD=2/3AB, the ratio of the length of BC to the length of DE is A. 1/6 B. 1/4 C. 3/2 D. 3/4
Answer:
The correct answer is c
Step-by-step explanation:
Answer:
C.) 3/2
Explanation:
PLATO
Find the standard form of the equation of the ellipse with the given characteristics and center at the origin. Foci: (±7, 0); major axis of length 18
Answer: [tex]\dfrac{x^2}{81}+\dfrac{y^2}{32}=1[/tex]
Step-by-step explanation:
The standard form of equation of ellipse with foci (±c,0) as:
[tex]\dfrac{x^2}{a^2}+\dfrac{y^2}{b^2}=1[/tex]
, where major axis = 2a and minor axis = 2b
Given: Foci: (±7, 0); major axis of length 18
i.e. c= 7 and 2a =18 ⇒a= 9
Also,
[tex]c^2=a^2-b^2\Rightarrow\ b^2= a^2-c^2\\\\\Rightarrow\ b^2={9^2-7^2}={81-49}\\\\\Rightarrow\ b^2=32[/tex]
Put value of [tex]a^2[/tex] and [tex]b^2[/tex] , we get the required equation :
[tex]\dfrac{x^2}{81}+\dfrac{y^2}{32}=1[/tex]
Suppose that 67.2% of all adults with type 2 diabetes also suffer from hypertension. After developing a new drug to treat type 2 diabetes, a team of researchers at a pharmaceutical company wanted to know if their drug had any impact on the incidence of hypertension for diabetics who took their drug. The researchers selected a random sample of 500 participants who had been taking their drug as part of a recent large-scale clinical trial and found that 317 suffered from hypertension.
The researchers want to use a one‑sample z ‑test for a population proportion to see if the proportion of type
2 diabetics who have hypertension while taking their new drug, p, is different from the proportion of all type
2 diabetics who have hypertension. They decide to use a significance level of ???? = 0.05.
A. Determine the p value for this test.
B. Determine the value of the z test statistic.
Answer: A. p-value = 0.04
B. z = - 1.77
Step-by-step explanation: To calculate z test statistic or z-score for a population proportion, first find the proportion (p-hat):
[tex]p_{hat}[/tex] = [tex]\frac{317}{500}[/tex] = 0.634
Then determine the standard deviation:
[tex]\sigma = \sqrt{\frac{p_{hat}(1-p_{hat})}{n} }[/tex]
[tex]\sigma = \sqrt{\frac{0.634(0.366)}{500} }[/tex]
[tex]\sigma = \sqrt{0.00046 }[/tex]
[tex]\sigma[/tex] = 0.0215
Calculating z-score:
[tex]z=\frac{p_{hat}-p}{\sigma}[/tex]
[tex]z=\frac{0.634-0.672}{0.0215}[/tex]
[tex]z=-1.77[/tex]
Z-test for the population proportion is z = - 1.77
P-value is the probability describing the data if null hypothesis is true, i.e.:
P(z< -1.77)
Using z-score table, the probability is:
P(z< -1.77) = 0.04
p-value = 0.04
P-value for this test is p-value = 0.04.
