0.1449 = 14.49% probability that 6 students or more will score an "A" on the final exam.
---------------
For each student, there are only two possible outcomes. Either they score an A, or they do not. The probability of a student scoring an A is independent of any other student, which means that the binomial probability distribution is used to solve this question.
Additionally, to find the proportion of students who scored an A, the normal distribution is used.
----------------
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 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 a success.
----------------
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean and standard deviation , 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.
----------------
Proportion of students that scored an A:
Scores have a mean of 79 and a standard deviation of 11.3, which means that [tex]\mu = 79, \sigma = 11.3[/tex]
Scores of 90 or higher are graded an A, which means that the proportion is 1 subtracted by the p-value of Z when X = 90, so:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{90 - 79}{11.3}[/tex]
[tex]Z = 0.97[/tex]
[tex]Z = 0.97[/tex] has a p-value of 0.8340.
1 - 0.8340 = 0.166
The proportion of students that scored an A is 0.166.
----------------
Probability that 6 students or more will score an "A" on the final exam:
Binomial distribution.
22 students, which means that [tex]n = 22[/tex]
The proportion of students that scored an A is 0.166, which means that [tex]p = 0.166[/tex]
The probability is:
[tex]P(X \geq 6) = 1 - P(X < 6)[/tex]
In which
[tex]P(X < 6) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5)[/tex]
Then
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 0) = C_{22,0}.(0.166)^{0}.(0.834)^{22} = 0.0184[/tex]
[tex]P(X = 1) = C_{22,1}.(0.166)^{1}.(0.834)^{21} = 0.0807[/tex]
[tex]P(X = 2) = C_{22,2}.(0.166)^{2}.(0.834)^{20} = 0.1687[/tex]
[tex]P(X = 3) = C_{22,3}.(0.166)^{3}.(0.834)^{19} = 0.2239[/tex]
[tex]P(X = 4) = C_{22,4}.(0.166)^{4}.(0.834)^{18} = 0.2117[/tex]
[tex]P(X = 5) = C_{22,5}.(0.166)^{5}.(0.834)^{17} = 0.1517[/tex]
Then
[tex]P(X < 6) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5) = 0.0184 + 0.0807 + 0.1687 + 0.2239 + 0.2117 + 0.1517 = 0.8551[/tex]
[tex]P(X \geq 6) = 1 - P(X < 6) = 1 - 0.8551 = 0.1449[/tex]
Thus
0.1449 = 14.49% probability that 6 students or more will score an "A" on the final exam.
For a problem that used the normal distribution, you can check https://brainly.com/question/15181104, and for a problem that used the binomial distribution, you can check https://brainly.com/question/15557838
ko dung may tinh hay so sanh
3√7 vs 7√3
Answer:
what this makes bi sense haha
Step-by-step explanation:
but ok
37. The trip between 2 towns is exactly 90 miles. You have gone 40% of this distance. How far have
you gone?
Answer:
36 miles
Step-by-step explanation:
We want to find 40% of 90 miles
40% * 90
.40 * 90
36 miles
We have to find travelled distance inorder to find this we have to find 40℅ of 90miles
[tex]\\ \Large\sf\longmapsto 90\times 40\℅[/tex]
[tex]\\ \Large\sf\longmapsto 90\times \dfrac{40}{100}[/tex]
[tex]\\ \Large\sf\longmapsto 9\times 4[/tex]
[tex]\\ \Large\sf\longmapsto 36miles [/tex]
please help me with this question!
Answer:
12 miles
Step-by-step explanation:
Let the amount of hours it takes Leroy to catch up to Kevin equal x. Since speed multiplied by time is distance, Leroy would have run a total of 6x miles(6*x). Kevin already had a head start of 24 minutes, which is the same as 2/5 of an hour. In 2/5 an hour, Kevin ran 2 miles as 2 is 2/5 *5. For the next x hours his distance would be a total of 5x(5*x). This means, after x hours, Kevins distance is 5x + 2. In this case, catching up to someone is the same as having the same distance value. This means we can set the two expressions equal to each other, and solve:
6x = 5x + 2
x = 2
The time it took Leroy to catch up is 2 hours, but we are looking for the distance, which is represented by 6x. We substitute in 2 to get:
6(2) = 12
This means Leroy had to run 12 miles.
2 balloons and 3 cakes cost £29.
6 balloons and 4 cakes cost £52.
Find the cost of one of each.
1 balloon is £
1 cake is £
Answer:
1 balloon is 4/ 1 cake is 7
Step-by-step explanation:
2 balloons is 8/ 3 cakes are 21 add together you get 29.
18 Geometry question: Use an algebraic equation to find the measure of each angle that is representative in terms of X
Answer:
12x - 28° = 116°
7x + 32° = 116°
Step-by-step explanation:
12x - 28° and 7x + 32° are vertical angles. Vertical angles are congruent.
Therefore, to find the measure of each angle, we have to set each equation equal to each other as follows:
12x - 28° = 7x + 32°
Collect like terms
12x - 7x = 28 + 32
5x = 60
Divide both sides by 5
5x/5 = 60/5
x = 12
✔️12x - 28°
Plug in the value of x
12(12) - 28
= 144 - 28
= 116°
✔️7x + 32°
7(12) + 32
= 84 + 32
= 116°
-27
Which of the following is equivalent to
نان-۴
?
N
O
(197)
NI
12
22
(22)
2².2
Answer:
3rd option
Step-by-step explanation:
(1/2)^-2t
= (2^-1)^-2t
= 2^2t
= (2^2)^t
Answered by GAUTHMATH
Please help
What are the roots (zeros) of the polynomial f(x)=x^3+3x^2-9x+15
9514 1404 393
Answer:
{-5.2555, 1.1278 ± 1.2579i}
Step-by-step explanation:
Descarte's rule of signs tells you there are 0 or 2 positive real roots and 1 negative real root. A graph shows you the negative roots is irrational, and the positive roots are complex.
There are formulas for solving equations of this sort. The method you use will depend on whether you need an exact result or just a numerical approximation. Exact results can be obtained in terms of radicals or in terms of trig functions.
The first attachment is from a freely available solver. It gives 4 decimal places, which is sufficient for many purposes.
The second attachment is the graph, along with the quadratic that results from dividing f(x) by the factor that gives the real root. While the values shown on the graph are to 3 decimal places, the calculator can be used to find them to greater precision. (We have used Newton's Method iteration to find the real root to 12 significant figures.)
Find the range of the function represented by the list of ordered pairs below.
{(−9,4),(−6,3),(−3,0),(−2,−4)}
Answer:
(4,3,0,-4)
May this
help you
PLEASE HELP AND BE RIGHT PLEASE AND THANK YOU
Answer:
4 units
Step-by-step explanation:
A'B' = 2 × AB
8 = 2×AB
AB = 8/2 = 4
Answer:
16 units
Step-by-step explanation:
The triangle will get bigger because it has a scale factor that is greater than 1.
k=scale factor
k<1=reduction
k>1=enlargement
a) Show that 4x² -6x+9 is positive for all values real numbers x.
Answer:
(4x² -6x+1.5²) +9-1.5²= (2x-1.5)²+9-2.25= (2x-1.5)²+6.75
(2x-1.5)² is greater or equal to 0 , 6.75>0 so expression is positive for all real numbers x
Step-by-step explanation:
a) Use the formula a²-2ab+b²= (a-b)² (You need to make squared expression because it is always positive)
Consider 4x² as a² and -6x=-2ab
4x²=a² a=2x ab=3x 2x*b=3x
b=1.5
Express 4x² -6x+9= (4x² -6x+1.5²) +9-1.5²= (2x-1.5)²+9-2.25= (2x-1.5)²+6.75
(2x-1.5)² is greater or equal to 0 , 6.75>0 so expression is positive for all real numbers x
Tuition. The tuition at a community college increased from $2,500 to $2,650 per semester. What was the percent of increase in the tuition?
Answer:
6 percent increase
Step-by-step explanation:
2650 divided by 2500 gives you 1.06 which means if 2500 is 100 percent 2650 would be 106 percent so the answer is a 6 percent increase
Answer:
6%
Step-by-step explanation:
another way of doing this type of calculation is...
NEW-OLD = 2650-2500 = 150 = .06 = 6%
OLD 2500 2500
Question
(X-5y/y3)-1=
Answer:
[tex]x = y^3+5y[/tex]
Step-by-step explanation:
Complete question
[tex]\frac{x - 5y}{y^3} - 1=0\\[/tex]
Required
Solve for x
We have:
[tex]\frac{x - 5y}{y^3} - 1=0[/tex]
Collect like terms
[tex]\frac{x - 5y}{y^3} = 1[/tex]
Multiply through by [tex]y^3[/tex]
[tex]x - 5y = y^3[/tex]
Make x the subject
[tex]x = y^3+5y[/tex]
Find Easy question For yall
Answer:
V = 64.6
Step-by-step explanation:
Since this is a right triangle, we can use trig functions
cos V = adj side/ hypotenuse
cos V = 3/7
Taking the inverse cos of each side
cos ^-1 ( cos V) = cos ^-1 (3/7)
V=64.62306
Rounding to the nearest tenth
V = 64.6
Answer:
V=64.6
Step-by-step explanation:
the same thing as other guy, lol
An article in the November 1983 Consumer Reports compared various types of batteries. The average lifetimes of Duracell Alkaline AA batteries and Eveready Energizer Alkaline AA batteries were given as 4.1 hours and 4.5 hours, respectively. Suppose these are the population average lifetimes.
Required:
Let x̄ be the sample average lifetime of 64 Duracell and ȳ be the sample average lifetime of 64 Eveready Energizer batteries. What is the mean value of x̄- ȳ(i.e., where is the distribution of -centered)?
Answer:
The mean is of -0.4 hours.
Step-by-step explanation:
To solve this question, we need to understand the central limit theorem and subtraction of normal variables.
Central Limit Theorem
The Central Limit Theorem establishes 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].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
Subtraction between normal variables:
When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.
Mean of the sample of 64 Duracell:
By the Central Limit Theorem, 4.1 hours.
Mean of the sample of 64 Eveready:
By the Central Limit Theorem, 4.5 hours.
Mean of the difference?
Subtraction of normal variables, so we subtract the means.
4.1 - 4.5 = -0.4
The mean is of -0.4 hours.
The sum of the two numbers is 66. The larger number is 10 more than the smaller number. What are the numbers?
Answer:
28 and 38
Step-by-step explanation:
a+b = 66
a + 10 = b
using substitution, a + (a+10) = 66
2a = 56
a = 28
28 + 10 = 38
b = 38
On Fridays, Jerry stops at Steak & Taco Shack before he goes home. This week
his order was 1 steak sandwich, 2 orders of cheese fries, and 2 taco salads. He was
charged $11.50 before tax. One week ago, his order was 2 steak sandwiches, 3
orders of cheese fries, and 1 taco salad, and he was charged $15.25. Two weeks ago
he ordered 1 steak sandwich, 4 orders of cheese fries, and 1 taco salad, and was
charged $13. How much is 1 steak sandwich? How much is 1 cheese fries? How
much is 1 taco salad?
Answer:
Steak sandwich = x = 4
Cheese fries = y = 1.75
Taco salad = z = 2
Step-by-step explanation:
Let :
Steak sandwich = x
Cheese fries = y
Taco salad = z
This week:
x + 2y + 2z = 11.50 - - - - (1)
Last week :
2x + 3y + z = 15.25 - - - (2)
Two weeks ago :
x + 4y + z = 13 - - - - - (3)
Taking (1) and (2)
x + 2y + 2z = 11.50 ___(1)
2x + 3y + z = 15.25 ___(2)
Multiply (1) by 2 and (2) by 1 and subtract
2x + 4y + 4z = 23
2x + 3y + z = 15.25
_______________
y + 3z = 7.75 - - - - (4)
Taking (2) and (3)
2x + 3y + z = 15.25 - - (2)
x + 4y + z = 13 - - - - - (3)
Multiply (2) by 1 and (3) by 2 and subtract
2x + 3y + z = 15.25
2x + 8y + 2z = 26
______________
-5y - z = - 10.75 - - - - - (5)
Lets solve (4) and (5)
y + 3z = 7.75 - - - - (4) - - - multiply by 5
-5y - z = - 10.75 - - - - - (5) - - - multiply by 1
Then add the result :
5y + 15z = 38.75
-5y - z = - 10.75
____________
14z = 28
z = 28 / 14
z = 2
To find y ; put z = 2 in (4)
y + 3z = 7.75
y + 3(2) = 7.75
y + 6 = 7.75
y = 7.75 - 6
y = 1.75
From equation 3 ;
x + 4y + z = 13 - - - - - (3)
x + 4(1.75) + 2 = 13
x + 7 + 2 = 13
x + 9 = 13
x = 13 - 9
x = 4
Hence,
Steak sandwich = x = 4
Cheese fries = y = 1.75
Taco salad = z = 2
2+4? I am omisha please give me answer
Answer:
6
Step-by-step explanation:
2+4 = 6
..............
Answer:
Here is your answer omisha
2+4=6
Please help me with this
Answer:
[tex]\frac{121}{14} = 8\frac{9}{14}[/tex]
Step-by-step explanation:
Find the Sample size for 99% confidence level with a margin of error of 4% and p unknown.
Answer:
za/2: Divide the confidence level by two, and look that area up in the z-table: .95 / 2 = 0.475. ...
E (margin of error): Divide the given width by 2. 6% / 2. ...
: use the given percentage. 41% = 0.41. ...
: subtract. from 1.
!!!Please help!!!
What is the following quotient?
96
B
O 2.13
4.
2.V22
12
Please show work will mark you brainliest!
QUESTION:- An artist uses 200 tiles to create a tessellation design that covers a rectangle with dimensions 2 ft by 3 ft. He will cover a wall with dimensions 10 ft by 15 ft using the same design and tiles of the same size. How many tiles will he need to cover the entire wall?
ANSWER:-
CASE 1 :- NUMBER OF TILES USED -> 200AREA WHICH IS TO BE COVERED-> 2×3 ft² (given-> rectangle)CASE 2:-
AREA WHICH IS TO BE COVERED-> 10×15 ft² (given-> rectangle)NUMBER OF TILES:- TO FINDIT IS GIVEN THAT DESIGN AND SIZE OF TILES R SAME SO WE CAN CONSIDER THAT SAME NUMBER OF TILES WILL COVER SAME AREA IN BOTH CASE.
WE CAN USE UNITARY METHOD FOR SOLVING THIS:-
[tex]6ft² \: is \: covered \: using \: 200 \: tiles \\ 1ft² \: is \: covered \: using \: \frac{200}{6} \: tiles \\ 150ft² \: is \: covered \: using \: \frac{200 \times 150}{6} \: tiles \\ 150ft² \: is \: covered \: using \: \frac{200 \times \cancel{150}^{ \: \: 25} }{ \cancel6 {}^{ \: 1} } \: tiles \\ 150ft² \: is \: covered \: using \: 200 \times 25 \: tiles \\ 150ft² \: is \: covered \: using \: 5000 \: tiles[/tex]
PLEASE HELP!!
Indicate the method you would use to prove the two ▵‘s ≅. If no method applies, enter “none”
A. SSS
B. SAS
C. ASA
D. AAS
E. None
(I attached the triangle thing that goes with the question)
The operations manager of a company that manufactures tires wants to determine whether there are any differences in the quality of work among the three daily shifts. She randomly selects 300 tires and carefully inspects them. Each tire is either classified as perfect, satisfactory, or defective, and the shift that produced it is also recorded. The two categorical variables of interest are "shift" and "condition of the tire produced". The p-value of the Chi-Squared test of independence is 0.073. Does the data provide sufficient evidence at the 5% significance level to infer that there are differences in quality among the three shifts?
The operation manager is responsible to identify whether there are errors in quality of the tires manufactured.
There are three different shifts and each shift has different team of workers who manufacture tires. For this we test hypothesis as;
H0 ; Quality of tire manufactured is independent on shifts
Ha ; Quality of tires manufactured is dependent on shifts.
The p value of chi squared test is greater than the significance level therefore we reject the null hypothesis.
This hypothesis reach to conclusion that quality of tires is dependent on shifts, which means there are differences in quality among the three shifts.
Learn more at https://brainly.com/question/24365931
4 times a certain number less two times that's the same number is 10 what is the number
Answer:
The number is 5
Step-by-step explanation:
Let the number be x,
Four times the number= 4x
two times the same number= 2x
So we have ,
4x – 2x = 10
2x = 10
x = 5
Therefore the number is 5
Solve.
x^2-9x+3=0
x=
or
x=
What is the area of this figure?
Answer:
22
Step-by-step explanation:
(5x2) + (3x2) + (3x2)
22 square units
Answer from Gauthmath
A walking path across a park is represented by the equation y = -4x+10. A
new path will be built perpendicular to this path. The paths will intersect at
the point (4.-6). Identify the equation that represents the new path.
102
10
10
O A. y -**-5
B. y --4x+10
C. y - 4x-22
O D. v-**-7
first invert fraction of the slope from 4/1 to 1/4 and switch sign. then figure out the y-intercept
the algebraic approach would work like this:
-4x + 10 = 1/4x + b
plug in what you got, here: the intersection information
-4*(4) + 10 = 1/4*(4) + b
-16 + 10 = 1 + b
-6 = 1 + b
-7 = b
The management of a large airline wants to estimate the average time after takeoff taken before the crew begins serving snacks and beverages on their flights. Assuming that management has easy access to all of the information that would be required to select flights by each proposed method, which of the following would be reasonable methods of stratified sampling?
a. For each day of the week, randomly select 5% of all flights that depart on that day of the week.
b. Divide all flights into the following 4 groups on the basis of scheduled departure time: before 9:00 am 9:00 am to 1:00 pm. 1:00 pm to 5:00 pm, and after 5:00 pm. Randomly select 5% of the flights in each group.
c. For each crew member the airline employs, randomly select 5 flights that the crew member works.
d. Divide the airports from which the airline's fights depart into 4 regions: Northeast, Northwest Southwest and Southeast. Randomly select 5% of all flights departing from airports in each region
Answer:
The answer is "Option a, Option b, and Option d".
Step-by-step explanation:
In the given question it is used to stratifying the sampling if the population of this scenario it flights takes off when it is divided via some strata.
In option a, In this case, it stratified the sampling, as the population of planes taking off has been divided into the days of the week. In option b, It also used as the case of stratified sampling. In options c, it is systematic sampling, that's why it is wrong. In option d, It is an example of stratifying the sampling.Answer:
For each day of the week, randomly select 5% of all flights that depart on that day of the week.
Divide all flights into the following 4 groups on the basis of scheduled departure time: before 9:00 am, 9:00 am to 1:00 pm, 1:00 pm to 5:00 pm, and after 5:00 pm. Randomly select 5% of the flights in each group.
Divide the airports from which the airline's flights depart into 4 regions: Northeast, Northwest, Southwest, and Southeast. Randomly select 5% of all flights departing from airports in each region.
Step-by-step explanation:
ll sampling methods that divide the flights into a small number of mutually exclusive categories are appropriate. These methods include all flights on the basis of a characteristic that might be associated with the variable being investigated and randomly selects a proportionate number of flights from each group.
The graph f(x)=x^5 is transformed to form a new function, g(x). Which set of transformations takes f(c) to g(x) in the correct order?
- translation 2 units to right,vertical stretch by a factor 1/3, translation 1 unit up
-translation 2 units to the right, vertical stretch by a factor of 3, translation 1 unit up
-translation 2 units to the right,translation 1 unit up,vertical stretch by a factor of 1/3
-translation 2 units to the right,translation 1 unit up,vertical stretch by a factor of 3
Answer:
Translation 2 units to the right
Vertical stretch by a factor of 3
Translation 1 unit up
Step-by-step explanation:
Correct on plato :}
A 90% confidence interval is (35 45). What is the margin of error?
A. 5
B.4.5
C.9
D.10
Answer:
option A 5
I hope it's correct
.....
