Answer:
150
Step-by-step explanation:
Increase = New Number - Original Number.
divide the increase by the original number and multiply the answer by 100.
I hope this helped! :)A professor knows that her statistics students' final exam scores have a mean of 79 and a standard deviation of 11.3. In his class, an "A" is any exam score of 90 or higher. This quarter she has 22 students in her class. What is the probability that 6 students or more will score an "A" on the final exam?
prob =
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
If two resistors with resistances R1 and R2 are connected in parallel, as in the figure below, then the total resistance R, measured in ohms (Ω), is given by 1/R = 1/R1 + 1/R2 . If R1 and R2 are increasing at rates of 0.3 Ω/s and 0.2 Ω/s, respectively, how fast is R changing when R1 = 60 Ω and R2 = 80 Ω? (Round your answer to three decimal places.)
The rate of change of R with time in the given equation is 0.004 ohm/s
Given parameters:
[tex]\frac{1}{R} = \frac{1}{R_1} + \frac{1}{R_2} \\\\\frac{dR_1}{dt} = 0.3 \ ohm/s\\\\\frac{dR_2}{dt} = 0.2 \ ohm/s\\\\R_1 = 60 \ ohms\\\\R_2 = 80 \ ohms[/tex]
To find:
The rate of change of R with time in the given equation.First determine the value of R from the given equation;
[tex]\frac{1}{R} = \frac{1}{R_1} + \frac{1}{R_2} \\\\\frac{1}{R} = \frac{1}{60} + \frac{1}{80} \\\\\frac{1}{R} = \frac{4 + 3}{240} \\\\\frac{1}{R} = \frac{7}{240} \\\\R = \frac{240}{7} = 34.286 \ ohms[/tex]
Finally, to determine the rate of change of R, differentiate the given equation.
[tex]\frac{-1}{R^2} \frac{dR}{dt} = \frac{-1}{R_1^2} \frac{dR_1}{dt} - \frac{1}{R_2^2} \frac{dR_2}{dt} \\\\\frac{1}{R^2} \frac{dR}{dt} = \frac{1}{R_1^2} \frac{dR_1}{dt} + \frac{1}{R_2^2} \frac{dR_2}{dt}\\\\\frac{dR}{dt} = R^2(\frac{1}{R_1^2} \frac{dR_1}{dt} + \frac{1}{R_2^2} \frac{dR_2}{dt})[/tex]
[tex]\frac{dR}{dt} = 34.286(\frac{1}{(60)^2} \times 0.3 \ \ \ + \ \ \ \frac{1}{(80)^2} \times 0.2)\\\\\frac{dR}{dt} = 34.286(8.333 \times 10^{-5} \ \ \ + \ \ \ 3.125 \times 10^{-5})\\\\\frac{dR}{dt} = 34.286(11.458 \times 10^{-5})\\\\\frac{dR}{dt} = 0.00393\\\\\frac{dR}{dt} \approx 0.004 \ ohm/s[/tex]
Thus, from the given equation the rate of change of R with time is 0.004 ohm/s
Learn more here: https://brainly.com/question/14796851
Answer:
the verified answer is wrong.
Step-by-step explanation:
OP forgot to square R (34.286)
Can u please help I got 1 minnnn lefttttt
Answer:
26 cm
Step-by-step explanation:
P = 2a + 2b
a = side
b = base
Answer:
The area=base×height
=10×4
=40cm^2
perimeter=2(length+breadth)
I think to find the height Dc you use the pythagoras theorem of
Dc^2=de^2+ce^2
=√16+9
=5
therefore the perimeter will be
p=2(5+10)
=20cm
I hope this helps and sorry if it's wrong
5 people cleared a plot of land in 15 days. How many people would I need to hire to clear three times that plot in 5 days?
Please answer this and show the work/explain for me
2/7m - 1/7 = 3/14
What is
88x3-7+198-34x15+76-126=
-105
Multiply first, then subtract, then add.
Answer: the answer would be -105.
Plzzz I’m giving a away 25 points
Answer:
sin ß = opposite / hypotenuse
sin45° = x / 4√2
Cross multiply
x = sin 45° × 4√2
x = √2/2 × 4√2
x = 4 × √2 ×√2 / 2
x = 4 × 2 / 2
x = 8 / 2
x = 4
An ice cream store determines the cost of its sundaes by using the formula C = 0.50s + 0.35n + 0.25t, where C is the total cost in dollars, s is the number of scoops of ice cream, n is the number of scoops of nuts, and t is the number of liquid toppings. A Nutty Sundae costs $3.55. It has 3 scoops of nuts and 2 different liquid toppings. How many scoops of ice cream are in this sundae?
Answer:
4 scoops of ice cream
Step-by-step explanation:
Plug in the total cost, number of scoops of nuts, and number of liquid toppings into the formula. Then, solve for s:
C = 0.50s + 0.35n + 0.25t
3.55 = 0.50s + 0.35(3) + 0.25(2)
3.55 = 0.50s + 1.05 + 0.5
3.55 = 0.50s + 1.55
2 = 0.50s
4 = s
So, the sundae had 4 scoops of ice cream.
ive gotten it wrong like 4 times n i cannot figure it out pls help
Answer:
x = 74.74 m
Step-by-step explanation:
you need simple trigonometry to solve it
cosine of an angle is the ratio of the adjacent side to the hypotenuse
cos(42.2) is about 0.74
so X / Hypotenuse = 0.74
we know hypotenuse is 101 m
X / 101 = 0.74
x = 74.74 m
hope this helped!
Nick needs one more class to complete his schedule. There are 5 writing classes, 3 history classes, and 4 mathematics classes that can fit into his schedule. If Nick chooses a class at random, what is the probability that he chooses a history class? Give your answer as a fraction.
Answer:
1/4
Step-by-step explanation:
Probability = 3/(5+3+4)
= 3/12 or 1/4
The retail of a price of an LCD TV was $7000 what was the original price before the GST of 10% was added?
Answer:
$636.36
Step-by-step explanation:
7000 = 110% of total cost
Try to get it to 100 percent
700/11 = 63.(63)
63.(63)*10= 636.36
For Americans using library services, the American Library Association claims that at most 67% of patrons borrow books. The library director in Owensboro, Kentucky feels this is not true, so she asked a local college statistic class to conduct a survey. The class randomly selected 100 patrons and found that 82 borrowed books. Did the class demonstrate that the percentage was higher in Owensboro, KY? Use α = 0.01 level of significance. What is the possible proportion of patrons that do borrow books from the Owensboro Library?
Answer:
The p-value of the test is 0.0007 < 0.01, which means that the class demonstrates that the percentage was higher in Owensboro, KY.
The possible proportion of patrons that do borrow books from the Owensboro Library is 0.82.
Step-by-step explanation:
For Americans using library services, the American Library Association claims that at most 67% of patrons borrow books. Test if the proportion is higher in Owensboro, KY.
At the null hypothesis, we test if the proportion is of at most 0.67, that is:
[tex]H_0: p \leq 0.67[/tex]
At the alternative hypothesis, we test if the proportion is of more than 0.67, that is:
[tex]H_1: p > 0.67[/tex]
The test statistic is:
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.
0.67 is tested at the null hypothesis:
This means that [tex]\mu = 0.67, \sigma = \sqrt{0.67*0.33}[/tex]
The class randomly selected 100 patrons and found that 82 borrowed books.
This means that [tex]n = 100, X = \frac{82}{100} = 0.82[/tex]
Value of the test statistic:
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
[tex]z = \frac{0.82 - 0.67}{\frac{\sqrt{0.67*0.33}}{\sqrt{100}}}[/tex]
[tex]z = 3.19[/tex]
P-value of the test and decision:
The p-value of the test is the probability of a finding a sample proportion of 0.82 or above, which is 1 subtracted by the p-value of z = 3.19.
Looking at the z-table, z = 3.19 has a p-value of 0.9993.
1 - 0.9993 = 0.0007
The p-value of the test is 0.0007 < 0.01, which means that the class demonstrates that the percentage was higher in Owensboro, KY.
What is the possible proportion of patrons that do borrow books from the Owensboro Library?
The sample proportion of 0.82.
Stuck on this one!!
Shelly believes the honor roll students at her school have an unfair advantage in being assigned to the math class they request. She asked 500 students at her school the following questions: "Are you on the honor roll?" and "Did you get the math class you requested?" The results are shown in the table below:
Honor roll Not on honor roll Total
Received math class requested 125 215 340
Did not get math class requested 80 80 160
Total 205 295 500
Help Shelly determine if all students at her school have an equal opportunity to get into the math class they requested. Show your work, and explain your process for determining the fairness of the class assignment process.
Answer: No, there isn't equal opportunity
======================================================
Explanation:
Let's define the two events
A = person is on the honor rollB = person got the math class they requestedFrom the table, we see that
P(B) = 340/500 = 0.68
meaning that there's a 68% chance of picking someone who got the class they wanted (i.e. 68% of the people got the class they wanted)
------------
Now let's assume that the person is on the honor roll. This means we only focus on the "honor roll" column. There are 125 people here that got the class they wanted out of 205 honor roll students total.
So,
P(B given A) = 125/205 = 0.609756
which rounds to 0.61
This says that if a person is on the honor roll, then they have roughly a 61% chance of getting the class they want.
The chances have gone down from 68% to 61% roughly.
------------
It appears that being on the honor roll does affect your chances of getting into the class you want.
Therefore, all students do not have the same equal opportunity.
We would need to have P(B) and P(A given B) to be the same exact value for true equal opportunity to happen.
All students do not have equal opportunity.
From the table, we have the following parameters:
205 people are on honor roll call340 people got the math class requested500 people were surveyedThe above means that:
The probability that a person is on honor roll call is:
p1 = 205/500
p1 = 0.41
The probability that a person got the math class requested
p2 = 340/500
p2 = 0.68
Both probabilities are not equal.
Hence, it is true that all students do not have equal opportunity.
Read more about probability at:
https://brainly.com/question/25870256
Cho A=( căn x -4x /1-4x -1) : (1+2x/1-4x -2căn x/ 2căn x -1 -1)
Answer:
0.85714285714286 x 100 = 85.7143%.
Step-by-step explanation:
a principal of $1500 is invested at 5.5 interest compounded annually. how much will the investment be worth after 7 years
Answer:
Step-by-step explanation:
1500(1.055)^7= 2182.02
Use AABC to find the value of sin B.
Answer:
35/37
Step-by-step explanation:
sin(B)=(AC)/(AB) = 35/37
Four friends go to the movies. How many different ways can they sit in a row?
Answer:
120 ways
..................
Answer:
24
Step-by-step explanation:
4 friends
1st seat: 4 different people could sit here
Now there are 3 friends left
2nd seat: 3 different people could sit here
Now there are 2 friends left
3rd seat: 2 different people could sit here
Now there are 1 friends left
4th seat: 1 different people could sit here
4*3*2*1
24 ways
(b) If 124n= 232 five, find n.
Answer:[tex]n=\frac{58}{31}[/tex]
Step-by-step explanation:
[tex]124n=232\\\frac{124n}{124}=\frac{232}{124}\\n=\frac{232}{124}=\frac{58}{31}[/tex]
The value of n is 18.75. To find the value of n, we need to solve the equation: 124n = 232 five
Let's first convert "232 five" into a numerical value:
"232 five" means 2325 (since five is in the units place).
Now, the equation becomes:
124n = 2325
To solve for n, divide both sides of the equation by 124:
n = 2325 / 124
Now, perform the division:
n = 18.75
So, the value of n is 18.75.
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You play a game where you roll a single die. You pay $1 to play, and the payouts are $0.50 if you roll an
even number, $2 if you roll a 1, and $1 if you roll a 3 or 5. What are the odds for winning money if you play this game? Show your work and Explain.
Let W be the random variable representing your winnings from playing the game. Then
[tex]P(W=w)=\begin{cases}\text{prob. of rolling an even number}=\frac12&\text{if }w=\$0.50-\$1=-\$0.50\\\text{prob. of rolling a 1}=\frac16&\text{if }w=\$2-\$1=\$1\\\text{prob. of rolling 3 or 5}=\frac13&\text{if }w=\$1-\$1=\$0\\0&\text{otherwise}\end{cases}[/tex]
In short, you have a 1/6 chance of profiting from the game, and a 5/6 chance of losing money. So the odds of winning are (1/6)/(5/6) = 1/5 or 1 to 5.
Each side of a regular polygon is 3.2 cm in length. The perimeter of the polygon is 19.2 cm. How many sides does the polygon have? What is the name of the polygon?
Answer:
The polygon consists of 6 sides and the given polygon is a regular hexagon.
Step-by-step explanation:
The definition of perimeter is the total measure of the side lengths of a polygon. If the polygon said is regular, it means the polygon has equal sides and equal angles.
So the perimeter of a regular polygon is given by the formula:
P = (length of one side) x (number of sides)
In this case, the perimeter of the polygon is 19.2 cm and one side is equal to 3.2 cm.
DIVIDE (use the formula but in division to maintain a proportonal relationship):
19.2 ÷ 3.2 = 6
You could alsk check if its correct using the formula:
19.2 = 3.2 x 6 (TRUE)
A 6 sided regular polygon is known as a HEXAGON.
Hope this helps!
help please! I need the answer quickly! thank you!
Answer:
B) 1 unit to the left
Step-by-step explanation:
What is the measure of the unknown angle?
Image of a straight angle divided into two angles. One angle is thirty five degrees and the other is unknown.
Answer:
145
Step-by-step explanation:
Angles in a straight line = 180
So,
Let unkown angle be x,
x+35=180
x=180-35
x=145
sketch the graph of y=x(x-6)^
Answer:
i have attached pic of the graph
i hope this helps you
The number of people attending graduate school at a university may be
modeled by the quadratic regression equation y = 8x2 - 40x+6, where x
represents the year. Based on the regression equation, which year is the best
prediction for when 1206 people will attend graduate school?
A. Year 15
B. Year 18
C. Year 24
D. Year 20
Answer:
15 years
Step-by-step explanation:
Given the quadratic regression model:
y = 8x² - 40x+6 ; where
y = Number of people attending graduate school ;
x = number of years
The value of x when y = 1206
The equation becomes :
1206 = 8x² - 40x+6
1206 - 6 = 8x² - 40x
1200 = 8x² - 40x
Divide through by 8
150 = x² - 5x
x² - 5x - 150 = 0
x² - 15x + 10x - 150 = 0
x(x - 15) + 10(x - 15)
x - 15 = 0 or x + 10 = 0
x = 15 or x = - 10
Number of years can't be negative,
Hence, x = 15 years
Suppose y varies inversely with x, and y = 32 when x = 4. What is the value of y when x = 8?
a. 1/8
b. 64
c. 16
d. 8
NO LINKS OR ANSWERING QUESTIONS YOU DON'T KNOW!!!
Answer:
16
Step-by-step explanation:
Inverse variation is of the form
xy = k where k is a constant
x=4 and y = 32
4*32 = k
128 = k
xy = 128
Let x = 8
8y = 128
Divide each side by 8
8y/8 = 128/8
y =16
What is the order of rotational symmetry for the figure?
A. 4 or more
B. 2
C. 1
D. 3
9514 1404 393
Answer:
C. 1
Step-by-step explanation:
The only rotation that maps the figure to itself is rotation by 360°. The rotational order is 1.
how do you change 79/8 to a decimal
Answer:
Divide 79 by 8
Step-by-step explanation:
79/8
= 9.875
Find f(3) given f(x) = -3x3 + 2x2 + 24
Answer:
-39
Step-by-step explanation:
A 100.0 m long polymer cable of uniform circular cross section and of diameter 0.4cm has a mass of 1885.0 gm. What is the mass density, of the polymer in kg/m3?
The mass density in kg/m3 will be - 15 x [tex]10^{-2}[/tex] Kg/m3.
We have a 100.0 m long polymer cable of uniform circular cross section and of diameter 0.4cm has a mass of 1885.0 gm.
We have to determine its mass density in kg/m3.
What is Mass density ?The amount of mass per unit volume present in the body is called its mass density.
According to question, we have -
Length of polymer cable = 100.0 m
diameter of polymer cable = 0.4 cm = 0.004 m
Therefore, its radius = 0.002 m
The mass density of the wire will be -
[tex]\rho =\frac{m}{\pi r^{2} l}[/tex]
[tex]\rho[/tex] = [tex]\frac{1885}{3.14 \times0.002 \times 0.002 \times 100 }[/tex]
[tex]\rho = \frac{1885}{0.001256}[/tex] = 1500796.1 g/m3
1 Kg = 1000g
1g = 1/1000kg
1500796.1g = 1500.7 Kg = 15 x [tex]10^{-2}[/tex] Kg
Therefore, mass density = 15 x [tex]10^{-2}[/tex] Kg/m3
Hence, the mass density in kg/m3 will be - 15 x [tex]10^{-2}[/tex] Kg/m3.
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What is the height of a room which is 8m long, 6m wide and contains 144 meters cube of air?
