Answer:
0.5675 = 56.75% probability that at least 22 of the 44 students selected are non-history majors.
Step-by-step explanation:
The students are chosen without replacement from the sample, which means that the hypergeometric distribution is used to solve this question. We are working also with a sample with more than 10 history majors and 10 non-history majors, which mean that the normal approximation can be used to solve this question.
Hypergeometric distribution:
The probability of x successes is given by the following formula:
[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}[/tex]
In which:
x is the number of successes.
N is the size of the population.
n is the size of the sample.
k is the total number of desired outcomes.
Combinations formula:
[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]
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Approximation:
We have to use the mean and the standard deviation of the hypergeometric distribution, that is:
[tex]\mu = \frac{nk}{N}[/tex]
[tex]\sigma = \sqrt{\frac{nk(N-k)(N-n)}{N^2(N-1)}}[/tex]
In this question:
88 + 88 = 176 students, which means that [tex]N = 176[/tex]
88 non-history majors, which means that [tex]k = 88[/tex]
44 students are selected, which means that [tex]n = 44[/tex]
Mean and standard deviation:
[tex]\mu = \frac{44*88}{176} = 22[/tex]
[tex]\sigma = \sqrt{\frac{44*88*(176-88)*(176-44)}{176^2(175-1)}} = 2.88[/tex]
What is the probability that at least 22 of the 44 students selected are non-history majors?
Using continuity correction, as the hypergeometric distribution is discrete and the normal is continuous, this is [tex]P(X \geq 22 - 0.5) = P(X \geq 21.5)[/tex], which is 1 subtracted by the p-value of Z when X = 21.5. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{21.5 - 22}{2.88}[/tex]
[tex]Z = -0.17[/tex]
[tex]Z = -0.17[/tex] has a p-value of 0.4325
1 - 0.4325 = 0.5675
0.5675 = 56.75% probability that at least 22 of the 44 students selected are non-history majors.
Now there is a square city of unknown size with a gate at the center of each side. There is a tree 20 b from the north gate. That tree can be seen when one walks 14 bu from the south gate, turns west and walks 1775 bu. Find the length of each side of the city.
Answer:
The length of each side of the city is 250b
Step-by-step explanation:
Given
[tex]a = 20[/tex] --- tree distance from north gate
[tex]b =14[/tex] --- movement from south gate
[tex]c = 1775[/tex] --- movement in west direction from (b)
See attachment for illustration
Required
Find x
To do this, we have:
[tex]\triangle ADE \sim \triangle ACB[/tex] --- similar triangles
So, we have the following equivalent ratios
[tex]AE:DE = AB:CB[/tex]
Where:
[tex]AE = 20\\ DE = x/2 \\ AB = 20 + x + 14 \\ CB = 1775[/tex]
Substitute these in the above equation
[tex]20:x/2 = 20 + x + 14: 1775[/tex]
[tex]20:x/2 = x + 34: 1775[/tex]
Express as fraction
[tex]\frac{20}{x/2} = \frac{x + 34}{1775}[/tex]
[tex]\frac{40}{x} = \frac{x + 34}{1775}[/tex]
Cross multiply
[tex]x *(x + 34) = 1775 * 40[/tex]
Open bracket
[tex]x^2 + 34x = 71000[/tex]
Rewrite as:
[tex]x^2 + 34x - 71000 = 0[/tex]
Expand
[tex]x^2 + 284x -250x - 71000 = 0[/tex]
Factorize
[tex]x(x + 284) -250(x + 284)= 0[/tex]
Factor out x + 284
[tex](x - 250)(x + 284)= 0[/tex]
Split
[tex]x - 250 = 0 \ or\ x + 284= 0[/tex]
Solve for x
[tex]x = 250 \ or\ x =- 284[/tex]
x can't be negative;
So:
[tex]x = 250[/tex]
Find the missing length indicated
Answer:
what's the question? ke
Question 3 of 10
Which angle in ABC has the largest measure?
2
С
A ZA
B. 8
C. 20
O O
D. Cannot be determined
Answer:
Option C
Angle C has the largest measure
If a and b are positive numbers, find the maximum value of f(x) = x^a(2 − x)^b on the interval 0 ≤ x ≤ 2.
Answer:
The maximum value of f(x) occurs at:
[tex]\displaystyle x = \frac{2a}{a+b}[/tex]
And is given by:
[tex]\displaystyle f_{\text{max}}(x) = \left(\frac{2a}{a+b}\right)^a\left(\frac{2b}{a+b}\right)^b[/tex]
Step-by-step explanation:
Answer:
Step-by-step explanation:
We are given the function:
[tex]\displaystyle f(x) = x^a (2-x)^b \text{ where } a, b >0[/tex]
And we want to find the maximum value of f(x) on the interval [0, 2].
First, let's evaluate the endpoints of the interval:
[tex]\displaystyle f(0) = (0)^a(2-(0))^b = 0[/tex]
And:
[tex]\displaystyle f(2) = (2)^a(2-(2))^b = 0[/tex]
Recall that extrema occurs at a function's critical points. The critical points of a function at the points where its derivative is either zero or undefined. Thus, find the derivative of the function:
[tex]\displaystyle f'(x) = \frac{d}{dx} \left[ x^a\left(2-x\right)^b\right][/tex]
By the Product Rule:
[tex]\displaystyle \begin{aligned} f'(x) &= \frac{d}{dx}\left[x^a\right] (2-x)^b + x^a\frac{d}{dx}\left[(2-x)^b\right]\\ \\ &=\left(ax^{a-1}\right)\left(2-x\right)^b + x^a\left(b(2-x)^{b-1}\cdot -1\right) \\ \\ &= x^a\left(2-x\right)^b \left[\frac{a}{x} - \frac{b}{2-x}\right] \end{aligned}[/tex]
Set the derivative equal to zero and solve for x:
[tex]\displaystyle 0= x^a\left(2-x\right)^b \left[\frac{a}{x} - \frac{b}{2-x}\right][/tex]
By the Zero Product Property:
[tex]\displaystyle x^a (2-x)^b = 0\text{ or } \frac{a}{x} - \frac{b}{2-x} = 0[/tex]
The solutions to the first equation are x = 0 and x = 2.
First, for the second equation, note that it is undefined when x = 0 and x = 2.
To solve for x, we can multiply both sides by the denominators.
[tex]\displaystyle\left( \frac{a}{x} - \frac{b}{2-x} \right)\left((x(2-x)\right) = 0(x(2-x))[/tex]
Simplify:
[tex]\displaystyle a(2-x) - b(x) = 0[/tex]
And solve for x:
[tex]\displaystyle \begin{aligned} 2a-ax-bx &= 0 \\ 2a &= ax+bx \\ 2a&= x(a+b) \\ \frac{2a}{a+b} &= x \end{aligned}[/tex]
So, our critical points are:
[tex]\displaystyle x = 0 , 2 , \text{ and } \frac{2a}{a+b}[/tex]
We already know that f(0) = f(2) = 0.
For the third point, we can see that:
[tex]\displaystyle f\left(\frac{2a}{a+b}\right) = \left(\frac{2a}{a+b}\right)^a\left(2- \frac{2a}{a+b}\right)^b[/tex]
This can be simplified to:
[tex]\displaystyle f\left(\frac{2a}{a+b}\right) = \left(\frac{2a}{a+b}\right)^a\left(\frac{2b}{a+b}\right)^b[/tex]
Since a and b > 0, both factors must be positive. Thus, f(2a / (a + b)) > 0. So, this must be the maximum value.
To confirm that this is indeed a maximum, we can select values to test. Let a = 2 and b = 3. Then:
[tex]\displaystyle f'(x) = x^2(2-x)^3\left(\frac{2}{x} - \frac{3}{2-x}\right)[/tex]
The critical point will be at:
[tex]\displaystyle x= \frac{2(2)}{(2)+(3)} = \frac{4}{5}=0.8[/tex]
Testing x = 0.5 and x = 1 yields that:
[tex]\displaystyle f'(0.5) >0\text{ and } f'(1) <0[/tex]
Since the derivative is positive and then negative, we can conclude that the point is indeed a maximum.
Therefore, the maximum value of f(x) occurs at:
[tex]\displaystyle x = \frac{2a}{a+b}[/tex]
And is given by:
[tex]\displaystyle f_{\text{max}}(x) = \left(\frac{2a}{a+b}\right)^a\left(\frac{2b}{a+b}\right)^b[/tex]
PLEASE HELP!!!
Evaluate each expression.
(252) =
Answer:
1/5
Step-by-step explanation:
Consider rolling a fair die twice and tossing a fair coin nineteen times. Assume that all the tosses and rolls are independent.
The chance that the total number of heads in all the coin tosses equals 9 is(Q)_____ , and the chance that the total number of spots showing in all the die rolls equals 9 is(Q)__________ The number of heads in all the tosses of the coin plus the total number of times the die lands with an even number of spots showing on top (Q)______(Choose A~E)
a. has a Binomial distribution with n=31 and p=50%
b. does not have a Binomial distribution
c. has a Binomial distribution with n=21 and p=50%
d. has a Binomial distribution with n=21 and p=1/6
e. has a Binomial distribution with n=31 and p=1/6
Answer:
Hence the correct option is option c has a Binomial distribution with n=21 and p=50%.
Step-by-step explanation:
1)
A coin is tossed 19 times,
P(Head)=0.5
P(Tail)=0.5
We have to find the probability of a total number of heads in all the coin tosses equals 9.
This can be solved using the binomial distribution. For binomial distribution,
P(X=x)=C(n,x)px(1-p)n-x
where n is the number of trials, x is the number of successes, p is the probability of success, C(n,x) is a number of ways of choosing x from n.
P(X=9)=C(19,9)(0.5)9(0.5)10
P(X=9)=0.1762
2)
A fair die is rolled twice.
Total number of outcomes=36
Possibilities of getting sum as 9
S9={(3,6),(4,5)(5,4),(6,3)}
The total number of spots showing in all the die rolls equals 9 =4/36=0.1111
3)
The event of getting a good number of spots on a die roll is actually no different from the event of heads on a coin toss since the probability of a good number of spots is 3/6 = 1/2, which is additionally the probability of heads. the entire number of heads altogether the tosses of the coin plus the entire number of times the die lands with a good number of spots has an equivalent distribution because the total number of heads in 19+2= 21 tosses of the coin. The distribution is binomial with n=21 and p=50%.
Which expression is equivalent to the following complex fraction?
-25
245 5
+
y
3 2
у
Step-by-step explanation:
[tex] \longrightarrow \sf{ \dfrac{ \cfrac{ - 2}{x} + \cfrac{ 5}{y}}{\cfrac{ 3}{y} -\cfrac{ 2}{x} }} \\ \\ \longrightarrow \sf{ \dfrac{ \cfrac{ - 2y + 5x}{xy}}{\cfrac{ 3x - 2y}{xy} }} \\ \\ \longrightarrow \sf{ \cfrac{ - 2y + 5x}{xy}} \times{\cfrac{ xy}{3x - 2y} } \\ \\ \longrightarrow \boxed{ \sf{ \cfrac{ - 2y + 5x}{3x - 2y}}}[/tex]
Option A is correct!
The expression into an equivalent form would be; A [-2y + 5x ] / [3 x- 2y]
What are equivalent expressions?Those expressions that might look different but their simplified forms are the same expressions are called equivalent expressions.
To derive equivalent expressions of some expressions, we can either make it look more complex or simple. Usually, we simplify it.
[-2/x + 5/y] / [3/y - 2/x]
This expression could also be given by;
[-2y + 5x /xy] / [3 x- 2y /xy]
Now, we know that x would cancel out;
[-2y + 5x ] / [3 x- 2y]
Hence, the expression into an equivalent form would be; A [-2y + 5x ] / [3 x- 2y]
Learn more about expression here;
brainly.com/question/14083225
#SPJ2
The length L of the base of a rectangle is 5 less than twice its height H. Write the algebraic expression to model the area of the rectangle.
Answer:
Area of rectangle = 2H² - 5H
Step-by-step explanation:
Let the length be L.Let the height be H.Translating the word problem into an algebraic expression, we have;
Length =2H - 5
To write the algebraic expression to model the area of the rectangle;
Mathematically, the area of a rectangle is given by the formula;
Area of rectangle = L * H
Where;
L is the Length.H is the Height.Substituting the values into the formula, we have;
Area of rectangle = (2H - 5)*H
Area of rectangle = 2H² - 5H
Answer please answer!!
I need the answer asap
Answer:
35 cm
Step-by-step explanation:
is the correct answer
Use the graph to complete the statement. O is the origin. Ry−axis ο Ry=x: (-1,2)
A. (2, -1)
B. (-2, -1)
C. (-1, -2)
D. (1, -2)
Answer:
[tex](x,y) = (1,2)[/tex] -------- [tex]R_{y-axis}[/tex]
[tex](x,y)=(2,-1)[/tex] --------- [tex]R_{y=x}[/tex]
Step-by-step explanation:
Given
[tex](x,y) = (-1,2)[/tex]
Required
[tex]R_{y-axis}[/tex]
[tex]R_{y=x}[/tex]
[tex]R_{y-axis}[/tex] implies that:
[tex](x,y) = (-x,y)[/tex]
So, we have: (-1,2) becomes
[tex](x,y) = (1,2)[/tex]
[tex]R_{y=x}[/tex] implies that
[tex](x,y) = (y,x)[/tex]
So, we have: (-1,2) becomes
[tex](x,y)=(2,-1)[/tex]
I need help thanks you!
I think its C: 2 hours. sry if its wrong
The domain of a composite function (fog)(x) is the set of those inputs x in the domain of g for which g(x) is in the domain of f.
True
False
What is the equation of the line that passes through (-3,-1) and has a slope of 2/5? Put your answer in slope-intercept form
A: y= 2/5x -1/5
B: y= 2/5x +1/5
C: y= -2/5x -1/5
Answer:
y = 2/5x + 1/5
Step-by-step explanation:
y = 2/5x + b
-1 = 2/5(-3) + b
-1 = -6/5 + b
1/5 = b
Find the area of a rectangle that is 4-inches-wide and 15-inches-long.
Answer:
the area of a rectangle that is 4-inches-wide and 15-inches-long =15*4=60 square inches
[tex]\\ \sf\longmapsto Area=Length\times width[/tex]
[tex]\\ \sf\longmapsto Area=4(15)[/tex]
[tex]\\ \sf\longmapsto Area=60in^2[/tex]
Solve for x
X-8 = -10
A) X = 2
B) X = -2
C) X = 18
D) X = -18
Answer:
x=–2
Step-by-step explanation:
x-8=-10
x=-10-8
x=–2
Answer:
-8= -10
, = -10+8
, = -2
One third of number is four times eleven. What is half of that number
Answer:
One third of a number is four times eleven. What is the half of that number?
Explanation:
Four times 11 = 11 X 4 = 44
One third (1/3) of the number = 44
The number is = 44 X 3 = 132
Therefore half of the number 132 = 66
Answer:
66
Step-by-step explanation:
11 X 4 = 44
One third (1/3) of the number = 44
The number is = 44 X 3 = 132
Therefore half of the number 132 = 66
Work out the surface area of this solid quarter cylinder. give your answer in terms of pi. r:8cm h:15cm
Answer:
248 pi cm^2
Step-by-step explanation:
The surface area of a cylinder is given by
SA = 2 pi r^2 + pi rh where r is the radius and h is the height
= 2 pi( 8)^2 + pi (8)(15)
128 pi +120pi
248pi
Please help me with this
9514 1404 393
Answer:
1+3x = -89x = -30Step-by-step explanation:
If we let x represent "a number", then "three times a number" is 3x. The usm of that and 1 is ...
1 +3x . . . . . . the sum of 1 and 3 times a number
That is said to be -89, so we have the equation ...
1 +3x = -89
__
To solve this equation, we can subtract 1 from both sides:
3x = -90
Then we can divide by 3 to find x.
(3x)/3 = -90/3
x = -30
A basketball player averages 22.5 points scored per game with a standard deviation of 6.2 points. In one game, the athlete scored 10 points. What is the z-score for the points scored in this game?
–2.02
–1.63
1.63
2.02
Answer:
Step-by-step explanation:
Z -2.02
x 10
µ 22.5
σ 6.2
You need 675 mL of a 90% alcohol solution. On hand, you have a 25% alcohol mixture. How much of the 25% alcohol mixture and pure alcohol will you need to obtain the desired solution?
Answer:
90 ml of the 25 percent mixture and 585 of pure alcohol
Step-by-step explanation:
Firstly, you should find the quantity of alcohol in the desired mixture.
675:100*90= 675*0.9= 607.5
Firstly, define all the 25 percents mixure as x, the pure alcohol weight is y.
1. x+y= 675 (because the first and the second liquid form a desired liquid).
Then find the equation for spirit
The first mixture contains 25 percents. It is x/100*25= 0.25x
When the second one consists of pure alcohol, it contains 100 percents of spirit, so it is x.
2. 0.25x+y=607.5
Then you have a system of equations ( 1.x+y= 675 and 2. 0.25x+y= 607.5)
try 2-1 to get rid of y
x+y- (0.25x+y)= 675-607.5
0.75x= 67.5
x= 90
y= 675-x= 675-90= 585
It means that you need90 ml of the 25percents mixture and 585 0f pure alcohol
Alice and Bob each choose a number uniformly (and independently) from the interval [0, 10]. What is the probability that the absolute value of the difference between their two numbers is less than 1/4
Answer:
The probability is zero (0)
Step-by-step explanation:
Given;
interval of numbers to be chosen = 0, 1, 2, 3 , 4, 5, 6, 7, 8, 9 , 10
total possible outcome = 11
The possible numbers whose absolute difference is greater than ¹/₄ includes the following;
(0,1), (1,2), (2,3), (3,4), (4,5), (5,6), (6,7), (7,8), (8,9), (9,10), (10,0)
The probability of this = 11 / 11 = 1
The probability that the absolute value of the difference between their two numbers is less than 1/4
[tex]P(less \ than \ \frac{1}{4} ) = 1 - P(greater \ than \ \frac{1}{4} )\\\\P(less \ than \ \frac{1}{4} ) = 1 - 1 \\\\P(less \ than \ \frac{1}{4} ) = 0[/tex]
What is the quotient ? -4/2 divided by 2
Answer:
[tex]\frac{-\frac{4}{2} }{2} =-\frac{4}{2} *\frac{1}{2} =-\frac{4}{4} =-1[/tex]
what is the least common factor between 9 8 and 7
Answer:
504
Step-by-step explanation:
Using LCM the common multiple is 504 as shown in the image above.
There is a swimming pool which has a length of 15 m and a width of 12 m. There is a 2 m wide path around the pool. If the cost of the path is $5 per , what is the cost of the path? Use words, numbers, and/or symbols to justify your answer.
Answer:
15m+12m+15m+13m=54m
2m×12m=24m
Question
Express all real numbers less than -2 or greater than or equal to 3 in interval notation.
Real numbers can be expressed using the following interval,
[tex]\mathbb{R}=(-\infty,\infty)[/tex]
Of course infinities are not just normal infinities but thats out of the scope of this question.
Real numbers less than two can be expressed with,
[tex](-\infty,\infty)\cap(-\infty,-2)=\boxed{(-\infty,-2)}[/tex]
The [tex]\cap[/tex] is called intersection ie. where are both intervals valid. First we took real numbers then we intersected them with real numbers valued less than -2 and we got real numbers which are less than -2.
Similarly we can perform with "greater than or equal to 3" real numbers,
[tex](-\infty,\infty)\cap[3,\infty)=\boxed{[3,\infty)}[/tex]
So we have one interval stretching from negative infinity to (but not including) -2, and another interval stretching from including 3 to positive infinity.
If we want numbers in both intervals we can express this two ways,
First way is to use [tex]\cup[/tex] union operator to denote we want numbers from two intervals,
[tex]\boxed{(-\infty,2)\cup[3,\infty)}[/tex]
The second way is to specify which numbers we do not want, we do not want -2 and everything up to but not including 3, which is expressed with the following interval
[tex][-2,3)[/tex]
Now we just take out the not wanted interval from real numbers and we will remain with all wanted numbers,
[tex]\boxed{(-\infty,\infty)-[-2,3)}[/tex]
Hope this helps.
QUESTION 2
A board is 86 cm. in lenght and must be cut so that one piece is 20 cm. longer than the other piece
Find the lenght of each piece.
A26 cm and 60 cm
b. 33 cm and 53 cm
C 30 cm and 56 cm
d. 70 cm and 16 cm
One piece will be length x and the other piece will be 20 cm longer, so it will be x + 20 cm long.
Added together the length of these two boards will equal 86 cm. So you can write an equation:
x + (x + 20) = 86
Remove the parentheses and add the two x's together to get:
2x + 20 = 86
Subtract 20 from both sides:
2x = 66
Divide both sides by 2 and you have:
x = 33
The short piece is 33 cm and the other piece is 20 cm longer or 33 + 20 = 53 cm.
9+1+10+6×5+9+8×9+8+8+7+6+6+9+6+8+69+85+86+86+97+86+87+86+68
Step-by-step explanation:
hope it will help u
hope it will help u please mark me as brillient...
Answer:
939 is the answer
Step-by-step explanation:
plz Mark me as the brainlist
Find the area of the circle around your answer to the nearest 10th
Answer:
A= π ( 3.8)^2
A= 45.36
OAmalOHopeO
Step-by-step explanation:
area is 2xr(times your answer)
The graph of y= -2x + 10 is:
O A. a line that shows only one solution to the equation.
O B. a point that shows the y-intercept.
O C. a line that shows the set of all solutions to the equation.
O D. a point that shows one solution to the equation.
SUBM
9514 1404 393
Answer:
C. a line that shows the set of all solutions to the equation.
Step-by-step explanation:
Any graph shows the set of all solutions to the equation being graphed.
The graph of a linear function is a straight line.
Given that ƒ(x) = 3^x, identify the function g(x) shown in the figure. A) g(x) = −3^-x
B) g(x) = −(1∕3)^x
C) g(x) = 3^−x
D) g(x) = −3^x
Answer:
Option (D)
Step-by-step explanation:
From the graph attached,
Function 'f' is the reflected across x-axis to get the graph function 'g'.
Therefore, by definition of reflection across x-axis,
g(x) = -f(x)
g(x) = [tex]-3^x[/tex]
Option (D) will be the answer.
