Answer:
The probability that he answered neither of the problems correctly is 0.0625.
Step-by-step explanation:
We are given that a student ran out of time on a multiple-choice exam and randomly guess the answers for two problems each problem have four answer choices ABCD and only one correct answer.
Let X = Number of problems correctly answered by a student.
The above situation can be represented through binomial distribution;
[tex]P(X=r)=\binom{n}{r}\times p^{r}\times (1-p)^{n-r};x=0,1,2,3,....[/tex]
where, n = number of trials (samples) taken = 2 problems
r = number of success = neither of the problems are correct
p = probability of success which in our question is probability that
a student answer correctly, i.e; p = [tex]\frac{1}{4}[/tex] = 0.75.
So, X ~ Binom(n = 2, p = 0.75)
Now, the probability that he answered neither of the problems correctly is given by = P(X = 0)
P(X = 0) = [tex]\binom{2}{0}\times 0.75^{0}\times (1-0.75)^{2-0}[/tex]
= [tex]1 \times 1\times 0.25^{2}[/tex]
= 0.0625
In designing an experiment involving a treatment applied to 4 test subjects, researchers plan to use a simple random sample of 4 subjects selected from a pool of 31 available subjects. (Recall that with a simple random sample, all samples of the same size have the same chance of being selected.) Answer the question below.
What is the probability of each simple random sample in thiscase?
Answer:
The probability is [tex]p(n ) = 3.18*10^{-5}[/tex]
Step-by-step explanation:
From the question we are told that
The population size is N = 31
The sample size n = 4
Generally the number of way by which the n can be selected from N is mathematically represented as
[tex]\left N} \atop {}} \right. C_n = \frac{N! }{(N-n)!n!}[/tex]
=> [tex]\left 31} \atop {}} \right. C_4 = \frac{31! }{(31-4)!4!}[/tex]
=> [tex]\left 31} \atop {}} \right. C_4 = \frac{31 * 30 * 29 * 28* 27! }{27! * 4*3 * 2 * 1 }[/tex]
=> [tex]\left 31} \atop {}} \right. C_4 = \frac{ 755160 }{ 24}[/tex]
=> [tex]\left 31} \atop {}} \right. C_4 = 31465[/tex]
The number of ways of selecting a particular sample size is is [tex]k = 1[/tex]
Therefore the probability of each simple random sample in this case is mathematically evaluated as
[tex]p(n ) = \frac{1}{31465}[/tex]
[tex]p(n ) = 3.18*10^{-5}[/tex]
Given the graph, find an equation for the parabola.
Answer:
[tex]\Large \boxed{\sf \bf \ \ y=\dfrac{1}{16}(a-3)^2-2 \ \ }[/tex]
Step-by-step explanation:
Hello, please consider the following.
When the parabola equation is like
[tex]y=a(x-h)^2+k[/tex]
The vertex is the point (h,k) and the focus is the point (h, k+1/(4a))
As the vertex is (3,-2) we can say that h = 3 and k = -2.
We need to find a.
The focus is (3,2) so we can say.
[tex]2=-2+\dfrac{1}{4a}\\\\\text{*** We add 2. ***}\\\\\dfrac{1}{4a}=2+2=4\\\\\text{*** We multiply by 4a. ***}\\\\16a=1\\\\\text{*** We divide by 16. ***}\\\\a=\dfrac{1}{16}[/tex]
So an equation for the parabola is.
[tex]\large \boxed{\sf y=\dfrac{1}{16}(a-3)^2-2 }[/tex]
Hope this helps.
Do not hesitate if you need further explanation.
Thank you
 evaluate the expression for k=6 -18+2k=
Answer:
-6
Step-by-step explanation:
-18 + 2k wherre k = 6
=> -18 + 2(6)
=> -18 + 12
=> -6
Can someone please help me with this question?
Answer:
B
Step-by-step explanation:
11q + 5 ≤ 49
Subtract 5 from each side
11q + 5-5 ≤ 49-5
11q ≤44
Divide each side by 11
q ≤44/11
q≤4
There is a close circle at 4 because of the equals sign and the lines goes to the left
Answer:
B
Step 1:
To solve this, we need to isolate the variable q. To do so, we will subtract 5 from both sides of the inequality.
[tex]11q+5(-5)\leq 49(-5)\\11q\leq 44[/tex]
Step 2:
We divide both sides by 11 to get our q.
[tex]\frac{11q}{11}\leq \frac{44}{11} \\q\leq 4[/tex]
q ≤ 4
Step 3:
To find the correct graph, we need to know that a close circle means a ≤ or ≥ and an open one means a < or >. Here, we are using a ≤ so C and D are not our answers. Also remember that if the "arrow" is pointing left (<), then the arrow on the graph should be facing the left side. If the arrow is facing the right side, then that means we are using > or ≥. Here, we are using ≤ (left), so that means the arrow on the graph should be on a 4, facing left, with a closed circle.
Our answer is B.
PLEASE HELP ASAP WILL GIVE BRAINLIEST
how many meters are in 250 centimeters
Answer:
2.5 meters
Step-by-step explanation:
Write three fractions that are equivalent to 3 over 11 , but written in higher terms. One of them must
include one or more variables.
Answer:
Three fractions that are equivalent to [tex]\frac{3}{11}[/tex] are: [tex]\frac{6}{22}[/tex], [tex]\frac{24}{88}[/tex] and [tex]\frac{144}{528}[/tex].
Step-by-step explanation:
Equivalent fractions are set of fractions in which when simplified, they have the same answer.
Given: [tex]\frac{3}{11}[/tex]
i. multiply the numerator and denominator of [tex]\frac{3}{11}[/tex] by 2,
= [tex]\frac{3*2}{11*2}[/tex] = [tex]\frac{6}{22}[/tex]
i. multiply both the numerator and denominator of [tex]\frac{6}{22}[/tex] by 4,
= [tex]\frac{6*4}{22*4}[/tex]= [tex]\frac{24}{88}[/tex]
ii. multiply the numerator and denominator of [tex]\frac{24}{88}[/tex] by 6,
= [tex]\frac{24*6}{88*6}[/tex] = [tex]\frac{144}{528}[/tex]
So that;
[tex]\frac{3}{11}[/tex] = [tex]\frac{6}{22}[/tex] = [tex]\frac{24}{88}[/tex] = [tex]\frac{144}{528}[/tex].
Three fractions that are equivalent to [tex]\frac{3}{11}[/tex] are: [tex]\frac{6}{22}[/tex], [tex]\frac{24}{88}[/tex] and [tex]\frac{144}{528}[/tex].
Suppose that Y1, Y2,..., Yn denote a random sample of size n from a Poisson distribution with mean λ. Consider λˆ 1 = (Y1 + Y2)/2 and λˆ 2 = Y . Derive the efficiency of λˆ 1 relative to λˆ 2.
Answer:
The answer is "[tex]\bold{\frac{2}{n}}[/tex]".
Step-by-step explanation:
considering [tex]Y_1, Y_2,........, Y_n[/tex] signify a random Poisson distribution of the sample size of n which means is λ.
[tex]E(Y_i)= \lambda \ \ \ \ \ and \ \ \ \ \ Var(Y_i)= \lambda[/tex]
Let assume that,
[tex]\hat \lambda_i = \frac{Y_1+Y_2}{2}[/tex]
multiply the above value by Var on both sides:
[tex]Var (\hat \lambda_1 )= Var(\frac{Y_1+Y_2}{2} )[/tex]
[tex]=\frac{1}{4}(Var (Y_1)+Var (Y_2))\\\\=\frac{1}{4}(\lambda+\lambda)\\\\=\frac{1}{4}( 2\lambda)\\\\=\frac{\lambda}{2}\\[/tex]
now consider [tex]\hat \lambda_2[/tex] = [tex]\bar Y[/tex]
[tex]Var (\hat \lambda_2 )= Var(\bar Y )[/tex]
[tex]=Var \{ \frac{\sum Y_i}{n}\}[/tex]
[tex]=\frac{1}{n^2}\{\sum_{i}^{}Var(Y_i)\}\\\\=\frac{1}{n^2}\{ n \lambda \}\\\\=\frac{\lambda }{n}\\[/tex]
For calculating the efficiency divides the [tex]\hat \lambda_1 \ \ \ and \ \ \ \hat \lambda_2[/tex] value:
Formula:
[tex]\bold{Efficiency = \frac{Var(\lambda_2)}{Var(\lambda_1)}}[/tex]
[tex]=\frac{\frac{\lambda}{n}}{\frac{\lambda}{2}}\\\\= \frac{\lambda}{n} \times \frac {2} {\lambda}\\\\ \boxed{= \frac{2}{n}}[/tex]
where p is the price (in dollars) and x is the number of units (in thousands). Find the average price p on the interval 40 ≤ x ≤ 50. (Round your answer to two decimal places.)
THIS IS THE COMPLETE QUESTION BELOW
The demand equation for a product is p=90000/400+3x where p is the price (in dollars) and x is the number of units (in thousands). Find the average price p on the interval 40 ≤ x ≤ 50.
Answer
$168.27
Step by step Explanation
Given p=90000/400+3x
With the limits of 40 to 50
Then we need the integral in the form below to find the average price
1/(g-d)∫ⁿₐf(x)dx
Where n= 40 and a= 50, then if we substitute p and the limits then we integrate
1/(50-40)∫⁵⁰₄₀(90000/400+3x)
1/10∫⁵⁰₄₀(90000/400+3x)
If we perform some factorization we have
90000/(10)(3)∫3dx/(400+3x)
3000[ln400+3x]₄₀⁵⁰
Then let substitute the upper and lower limits we have
3000[ln400+3(50)]-ln[400+3(40]
30000[ln550-ln520]
3000[6.3099×6.254]
3000[0.056]
=168.27
the average price p on the interval 40 ≤ x ≤ 50 is
=$168.27
Translate the expression from algebra to words: 6+r
Answer:
a number, r, added to 6
Step-by-step explanation:
a number, r, added to 6
Answer:
a number, r, added to 6
Step-by-step explanation:
a number, r, added to 6
What is the correct answer and how can this be solved?
Answer:
[tex]$\mathbf{\frac{1}{19} }[/tex]
Step-by-step explanation:
[tex]$$\bullet \Nth \ Term;\\$$$\frac{n+2}{2n^{2} +3n-2}[/tex]
[tex]$$\bullet U_{10} \ Term;\\\\$$\boxed{\frac{(10+2) }{2*10^{2} +3*10-2}= \frac{1}{19} }[/tex]
Answer:
[tex]\boxed{\displaystyle \frac{1}{19}}[/tex]
Step-by-step explanation:
[tex]\displaystyle \frac{n+2}{2n^2 +3n-2}[/tex]
Replace n with 10 to find the 10th term.
[tex]\displaystyle \frac{10+2}{2(10)^2 +3(10)-2}[/tex]
Evaluate.
[tex]\displaystyle \frac{12}{2(100) +30-2}[/tex]
[tex]\displaystyle \frac{12}{200 +30-2}[/tex]
[tex]\displaystyle \frac{12}{228}[/tex]
Simplify.
[tex]\displaystyle \frac{1}{19}[/tex]
Suppose that the height (in centimeters) of a candle is a linear function of the amount of time (in hours) it has been burning. After 9 hours of burning, a candle has a height of 25.4 centimeters. After 23 hours of burning, its height is 19.8 centimeters. What is the height of the candle after 22 hours?
Answer:
Suppose that the height (in centimeters) of a candle is a linear function of
the amount of time (in hours) it has been burning.
After 11 hours of burning, a candle has a height of 23.4 centimeters.
After 30 hours of burning, its height is 12 centimeters.
What is the height of the candle after 13 hours?
:
Assign the given values as follows:
x1 = 11; y1 = 23.4
x2 = 30; y2 = 12
:
Find the slope using: m = %28y2-y1%29%2F%28x2-x1%29
m = %2812-23.4%29%2F%2830-11%29 = %28-11.4%29%2F19
:
Find the equation using the point/slope formula: y - y1 = m(x - x1)
y - 23.4 = -11.4%2F19(x - 11)
y - 23.4 = -11.4%2F19x + 125.4%2F19
y = -11.4%2F19x + 125.4%2F19 + 23.4
y = -11.4%2F19x + 125.4%2F19 + 23.4
y = -11.4%2F19x + 125.4%2F19 + 444.6%2F19
y = -11.4%2F19x + 570%2F19
y = -11.4%2F19x + 30, is the equation
:
What is the height of the candle after 13 hours?
x = 13
y = -11.4%2F19(13) + 30
y = -148.2%2F19 + 30
y = -7.8 + 30
y = 22.2 cm after 13 hrs
Simplify the following expression. 3x(4x − 3) A. 12x2 + 13x B. 12x2 + 5x C. 12x2 − 5x D. 12x2 − 9x
Answer:
Multiply using the distributive property.
D is the best answer.
Step-by-step explanation:
The simplified form of expression 3x (4x - 3) is 12x² - 9x.
What is an algebraic expression?An algebraic expression is consists of variables, numbers with various mathematical operations,
The given expression is,
3x (4x - 3).
Simplify the expression by solving bracket term,
3x × (4x) - 3 x (3x)
12x² - 9x
The given expression can be simplified as 12x² - 9x.
Hence, option (D) is correct.
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If f is a function that f(f(x)) = 2x² + 1, which is the value of f(f(f(f(3)))? Please help!
[tex]f(f(3))=2\cdot3^2+1=19\\f(f(f(f(3))))=2\cdot19^2+1=723[/tex]
Find the value of x.
A. 3
B. 9
C. 0
D. 12
Answer:
x=3
Step-by-step explanation:
(segment piece) x (segment piece) = (segment piece) x (segment piece)
3x(x+1) = 4x(x)
Divide each side by x
3x(x+1)/x = 4x(x)/x
3(x+1) = 4x
Distribute
3x+3 = 4x
Subtract 3x
3x+3-3x= 4x-3x
3 =x
Answer:
x = 3
Step-by-step explanation:
0 is a rediculas answer 9 and 12 are to big.
The lines are supposed to have a simular length:
3(3) + 4 = 13
4(3) + 3 = 15
These are the best answers that fit.
In order to earn an A in her math course,
Bernadette must have an average of at
least 90 on her exam scores. She has
grades of 83, 97, 89, and 82 on her first 4
exams. What is the minimum she can
score on the final exam to earn an A in the
course?
Step-by-step explanation:
Let minimum score on the final exam to earn an A be X
[tex]mean \: = \frac{sum \: of \: observation}{number \: of \: observation} [/tex]
[tex]90 = \frac{83 + 97 + 89 + 82 + x}{5} [/tex]
Further solving :
X = 99 marks
i need help asap please
Answer:
[tex]x = -\frac{3}{2}[/tex] or [tex]x = 1[/tex]
Step-by-step explanation:
Using the zero product property, first step is to set the given equation, [tex] 2x^2 + x - 1 = 2 [/tex] , to zero. Then factorise the left side.
Thus,
[tex] 2x^2 + x - 1 = 2 [/tex]
Subtract 2 from both sides
[tex] 2x^2 + x - 1 - 2 = 2 - 2 [/tex]
[tex] 2x^2 + x - 3 = 0 [/tex]
Factorise the left side
[tex] 2x^2 + 3x - 2x - 3 = 0 [/tex]
[tex] x(2x + 3) - 1(2x + 3) = 0 [/tex]
[tex] (x - 1)(2x + 3) = 0 [/tex]
Find the solution
[tex] x - 1 = 0 [/tex]
Or
[tex]2x + 3 = 0[/tex]
[tex] x = 1 [/tex]
Or
[tex]2x + 3 = 0[/tex]
[tex]2x = -3[/tex]
[tex]x = -\frac{3}{2}[/tex]
The answer is: [tex] x = 1 [/tex] or [tex]x = -\frac{3}{2}[/tex]
THE PRICE OF AN ITEM FROM $10 TO $17. WHAT WAS THE PERCENT INCREASE IN THE PRICE OF THE ITEM?
Answer:
70%
Step-by-step explanation:
The method to find out percentage increase is by subtracting the original price from the increased price and making it into a fractional form with the denominator as 10 (out of 100%). So it results to this.
(original price - increased price) / 10
(17 - 10) / 10 = 7/10
7/10 can be converted from its fractional form to 70% i.e.its percentage.
Hope this helps and please mark as the brainliest.
if pentagon OPQRS is dilated by a scale factor or ?
from the origin to create O'P'Q'R'S: what is the ordered pair of point S'?
Answer:
Option (D) : (3.5, 8.75)
Write down the answers to a,b,c,d
Answer:
(A) 1
(B) -2
(C) 3.5
(D) -0.5
Step-by-step explanation:
We can treat each thermometer like a vertical number line and read the values on each.
A is right on 1.
B is right on -2.
C is in the middle of 3 and 4, so 3.5
D is in the middle of 0 and -1, so -0.5
Hope this helped!
The triangle shown on the graph above is rotated 90 degrees clockwise about the original to form triangle P’Q’R which of the following are the (x,y) coordinates of the point P’
Hey there! I'm happy to help!
When rotating a point 90 degrees clockwise about the origin, our original point (x,y) becomes (-y,x), because it is now at a negative y-value.
We see that our point P is at (1,2). We can use this rotation formula to find the coordinates of P' (the new spot where P is)/
(x,y)⇒(-y,x)
(1,2)⇒(-2,1)
Therefore, the coordinates of the point P' are (-2,1).
Have a wonderful day! :D
PLEASE HELP!!
Solve for y
a) 8
b) 12
c) 3V7
d) 4V7
Answer:
C. [tex] y = 3\sqrt{7} [/tex]
Step-by-step explanation:
Based on the right triangle altitude theorem, the altitude, y, in the diagram above, equals the geometric mean of 9 and 7.
This implies => [tex] y = \sqrt{9*7} [/tex]
Thus, solve for y.
[tex] y = \sqrt{9} * \sqrt{7} [/tex]
[tex] y = 3\sqrt{7} [/tex]
The answer is C. [tex] y = 3\sqrt{7} [/tex]
What is the volume of a sphere, to the nearest cubic inch, if the radius equals 5 inches? Use π = 3.14.
Answer:
V = 523 in^3
Step-by-step explanation:
The volume of a sphere is given by
V = 4/3 pi r^3
V = 4/3 ( 3.14) * 5^3
V = 523.33333repeating
Rounding to the nearest inch^3
V = 523 in^3
Answer:
[tex] 523.6 {in}^{3} [/tex]
Step-by-step explanation:
[tex]v = \frac{4}{3} \pi {r}^{3} \\ = \frac{4}{3} \pi \times 5 \times 5 \times 5 \\ = 523.6 {in}^{3} [/tex]
If an image of a triangle is congruent to the pre-image, what is the scale factor of the dilation? 0.1 1 10
Answer:
1
Step-by-step explanation: diliation is like multiplilcation if you were to do 3*1 =3. simply congruent means all sides and angles are the same.
Given that the image and the preimage of the triangle are congruent, their
dimensions are the same.
The scale factor of dilation of an image of a triangle that is congruent to the pre-image is; 1Reasons:
Let ΔABC represent the preimage, and let ΔA'B'C' represent the image.
Given that the image and the preimage are congruent, we have;
AB ≅ A'B'
BC ≅ B'C'
AC ≅ A'C'
By definition of congruency, we have;
AB = A'B'
BC = B'C'
AC = A'C'
The scale factor of dilation is given as follows;
[tex]\displaystyle Scale \ factor = \mathbf{ \frac{A'B'}{AB}} = \frac{AB}{AB} = 1[/tex]Therefore;
If the image is congruent to the pre-image, the scale factor of dilation is; 1Learn more about dilation transformation here:
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Find the sum. 1. -7+(-5)
O-12
O-2
0 2
0 12
Answer:
-12
Step-by-step explanation:
-7+(-5)=
-7-5=
-12
The one-sample z ‑statistic for Thomas' statistical test has a value of −1.73346 , and Thomas calculates a P-value of 0.0830 . Should Thomas conclude that telephone surveys provide adequate coverage with respect to p ? Why or why not? Select all correct statements about his decision and conclusion.
Answer:
Thomas should not reject the null hypothesis.
Step-by-step explanation:
The null hypothesis is rejected or accepted on the basis of level of significance. When the p-value is greater than level of significance we fail to reject the null hypothesis and null hypothesis is then accepted. It is not necessary that all null hypothesis will be rejected at 10% level of significance. To determine the criteria for accepting or rejecting a null hypothesis we should also consider p-value. Here in this question the test value is -1.73346 and p-value is 0.0830. The p value is greater than the test value therefore the null hypothesis should be accepted.
The sum of two positive number is 6 times their difference. what is the reciprocal of the ratio of the larger number to the smaller?
let the numbers be a and b, a>b
a+b=6(a-b)
we need to find reciprocal of ratio of larger to smaller , which will be same as ratio of smaller to larger or b/a, let's call it x
divide the equation by a.
1+x=6(1-x)
on solving, x=5/7
Residents of four cities are able to vote in an upcoming regional election. A newspaper recently conducted a survey to gauge support for each of the two candidates. The results of the poll are shown in the two-way frequency table below.
Answer:
3 only
Step-by-step explanation:
Consider the statement, "The two cities with the highest number of respondents, both show more support for candidate A." In the total column, the two highest number of respondents are 471 and 463 which represent Carsonville and Appleton. For Carsonville, the number of respondents who prefer candidate A is 205, which is less than the number of respondents who prefer candidate B, 266. Therefore, this statement is not true.
Consider the statement, "The number of people who support candidate B in Carsonville is twice the number of people who support candidate B in New Thomas." In the table, the number of people who support candidate B in Carsonville is observed to be 266 and the number of people who support candidate B in New Thomas is 138. Since 266 is not equal to twice 138, this statement is not true.
Consider the statement, "More residents of Center City responded to the poll than the number who responded from New Thomas." In the total column, it can be observed that 350 people responded to the poll in Center City and 318 people responded to the poll in New Thomas. Since, 350 is greater than 318, this statement is true.
Consider the statement, "Overall, more residents support candidate A than candidate B." The bottom row of the table represents the total number of responses for each candidate. The number of people supporting candidate A is 797, which is less than the number of people supporting candidate B, 805. So, this statement is not true.
Therefore, the true statement is III only.
More residents of the center city responded to the pole than the number who responded from New Thomas, which is the only correct option. Option B. is correct.
Data given in the table shows the data of elections between two candidates among the different cities.
What is Statistic?
Statistics is the study of mathematics that deals with relations between comprehensive data.
I.The two cities with the highest number of respondents both show more support for candidate A. This statement is false because carsonville is the second highest support for A but it does not show more support for candidate A.
II.The number of people who support candidate B in Carsonville is twice the number of people who support candidate B in New Thomas. It is false
III. More residents of Center City responded to the pole than the number who responded from New Thomas. It is true.
IV. Overall, more residents support candidate A than candidate B. it is also false.
Thus, more residents of the center city responded to the pole than the number who responded from New Thomas, which is the only correct option. Option B. is correct.
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evaluate -99 + 3^2•5
Answer:
= - 54
Step-by-step explanation:
- 99 + 3^2•5
- 99 + 9 × 5
- 99 + 45
= - 54
Show that the set of functions from the positive integers to the set {0, 1, 2, 3, 4, 5, 6, 7, 8, 9} is uncountable. [Hint: First set up a one-to-one correspondence between the set of real numbers between 0 and 1 and a subset of these functions. Do this by associating to the real number 0.d1d2 . . . dn . . . the function f with f(n).
Answer:
since the set of functions expressed are uncountable and they are a subset of real numbers starting from N therefore the set {0,1,2,3,4,5,6,7,8,9} is uncountable as well as its off functions
Step-by-step explanation:
set = {0,1,2,3,4,5,6,7,8,9}
setting up a one-to-one correspondence between the set of real numbers between 0 and 1
The function : F(n)= {0,1} is equivalent to the subset (sf) of (n) , this condition is met if n belongs to the subset (sf) when f(n) = 1
hence The power set of (n) is uncountable and is equivalent to the set of real numbers given
since the set of functions expressed are uncountable and they are a subset of real numbers starting from N therefore the set {0,1,2,3,4,5,6,7,8,9} is uncountable as well as its offfunctions
