Answer:
Variables are used to represent an unknown quantity in a mathematical expression.
Step-by-step explanation:
Variables are used to represent an unknown quantity in a mathematical expression.For example : x + 2 = 4, here x is the variable.We can denote variable by any alphabet i.e, a,b,c,d etc.At a local community college, 57% of students who enter the college as freshmen go on to graduate. Five freshmen are randomly selected.
a. What is the probability that none of them graduates from the local community college? (Do not round intermediate calculations Round your final answer to 4 decimal places Probability
b. What is the probability that at most four will graduate from the local community college? (Do not round intermediate calculations. Round your final answer to 4 decimal places.)
c. What is the expected number that will graduate? (Round your final answer to 2 decimal places)
Answer:
a) 0.0147 = 1.47% probability that none of them graduates from the local community college.
b) 0.9398 = 93.98% probability that at most four will graduate from the local community college.
c) The expected number that will graduate is 2.85.
Step-by-step explanation:
For each student, there are only two possible outcomes. Either they will graduate, or they will not. The probability of a student graduating is independent of any other student graduating, which means that the binomial probability distribution is used to solve this question.
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 [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]
And p is the probability of X happening.
57% of students who enter the college as freshmen go on to graduate.
This means that [tex]p = 0.57[/tex]
Five freshmen are randomly selected.
This means that [tex]n = 5[/tex]
a. What is the probability that none of them graduates from the local community college?
This is P(X = 0). So
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 0) = C_{5,0}.(0.57)^{0}.(0.43)^{5} = 0.0147[/tex]
0.0147 = 1.47% probability that none of them graduates from the local community college.
b. What is the probability that at most four will graduate from the local community college?
This is:
[tex]P(X \leq 4) = 1 - P(X = 5)[/tex]
In which
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 5) = C_{5,5}.(0.57)^{5}.(0.43)^{0} = 0.0602[/tex]
So
[tex]P(X \leq 4) = 1 - P(X = 5) = 1 - 0.0602 = 0.9398[/tex]
0.9398 = 93.98% probability that at most four will graduate from the local community college.
c. What is the expected number that will graduate?
The expected value of the binomial distribution is:
[tex]E(X) = np[/tex]
In this question:
[tex]E(X) = 5*0.57 = 2.85[/tex]
The expected number that will graduate is 2.85.
A map was created using the scale 1 inch :25
miles. If the river is 5.5 inches long on the map, then it is actually how many miles long?
Suppose that on the average, 7 students enrolled in a small liberal arts college have their automobiles stolen during the semester. What is the probability that less than 1 student will have his automobile stolen during the current semester
Answer:
[tex]P(x>1)=0.9927[/tex]
Step-by-step explanation:
From the question we are told that:
Mean [tex]\=x =7[/tex]
Generally the Poisson equation for \=x is mathematically given by
[tex]P(x>1)=1-P(x \leq 1)[/tex]
Therefor
[tex]P(x>1)=1-(\frac{e^{-7}*7^0}{0!}+{\frac{e^{-7}*7^1}{1!})[/tex]
[tex]P(x>1)=1-(9.1*10^{-4}+6.3*10^{-3})[/tex]
[tex]P(x>1)=1-(7.3*10^{-3}[/tex]
[tex]P(x>1)=0.9927[/tex]
Is the collection og rall " student in set ? why ? class7
Answer:
in secret
Step-by-step explanation:
correct answer is in a secret
Find the direction cosines and direction angles of the vector. (Give the direction angles correct to the nearest degree.) c, c, c , where c > 0
Answer:
cos(∝) = 1/√3
cos(β) = 1/√3
cos(γ) = 1/√3
∝ = 55°
β = 55°
γ = 55°
Step-by-step explanation:
Given the data in the question;
vector is z = < c,c,c >
the direction cosines and direction angles of the vector = ?
Cosines are the angle made with the respect to the axes.
cos(∝) = z < 1,0,0 > / |z|
so
cos(∝) = < c,c,c > < 1,0,0 > / √[c² + c² + c²] = ( c + 0 + 0 ) / √[ 3c² ]
cos(∝) = c / √[ 3c² ] = c / c√3 = 1/√3
∝ = cos⁻¹( 1/√3 ) = 54.7356° ≈ 55°
cos(β) = < c,c,c > < 0,1,0 > / √[c² + c² + c²] = ( 0 + c + 0 ) / √[ 3c² ]
cos(β) = c / √[ 3c² ] = c / c√3 = 1/√3
β = cos⁻¹( 1/√3 ) = 54.7356° ≈ 55°
cos(γ) = < c,c,c > < 0,0,1 > / √[c² + c² + c²] = ( 0 + 0 + c ) / √[ 3c² ]
cos(γ) = c / √[ 3c² ] = c / c√3 = 1/√3
γ = cos⁻¹( 1/√3 ) = 54.7356° ≈ 55°
Therefore;
cos(∝) = 1/√3
cos(β) = 1/√3
cos(γ) = 1/√3
∝ = 55°
β = 55°
γ = 55°
The diameters of bolts produced in a machine shop are normally distributed with a mean of 5.8 millimeters and a standard deviation of 0.07 millimeters. Find the two diameters that separate the top 8% and the bottom 8%. These diameters could serve as limits used to identify which bolts should be rejected. Round your answer to the nearest hundredth, if necessary.
Answer:
5.70 < X < 5.89
Step-by-step explanation:
Z = ±1.40507156
z = (x - μ)/σ
1.40507156 = (x - 5.8)/.07
5.70 < X < 5.89
If the bearing of A from B is 125.Find the bearing of B from A
Answer:
305°
Step-by-step explanation:
The bearing in the reverse direction is 180° plus the bearing in the forward direction, that is
bearing of B from A = 180° + 125° = 305°
The vector w = ai + bj is perpendicular to the line ax + by = c and parallel to the line bx - ay = c. It is also true that the acute angle between intersecting lines that do not cross at right angles is the same as the angle determined by vectors that are either normal to the lines or parallel to the lines. Use this information to find the acute angle between the lines below.
5x + 9y = 2, 7x + 2y = 1
The angle is _______ radians.
(Type an exact answer, using pi as needed)
Answer:
fgvilgiuhuikj
Step-by-step explanation:??????????????
You work as an office assistant who does data entry for a large survey company. Data entry is performed in two-person teams: one person types and the other checks that person's work for errors. Each two-person team, on average, can enter the data of 520 surveys per day. A huge collection of 7,540 surveys will arrive tomorrow and must be entered by the end of the day. In order to enter all of the survey data, how many total employees, working in two-person teams, must work tomorrow?
Answer:
you just gave your self the answer because you just need to multiply
Step-by-step explanation:
15080 is the answer
PLEASE HELP :) I will give all points
answer choice a
x^2 - 5x - 1 = 0
a=1, b=-5, and c=-1
next you plug in the numbers into the quadratic formula
-(-5) plus or minus the square root of (-5)^2 - 4(1)(-1)/ 2(1)
after you simply, you should get 5 plus or minus the square root of 29, which is answer choice a
please help i am stuck on this assignment
Answer:
answer
x = -13/ 15, 0
Step-by-step explanation:
15x^2 + 13 x = 0
or, x(15x + 13) = 0
either, x = 0
or, 15x + 13 = 0
x = -13/15
Answer:
The answer should be C...............
imma sorry if I'm wrong
Graph g(x)=-8|x |+1.
Answer:
[tex] g(x)=-8|x |+1. = 9552815 \geqslant 6[/tex]
HELP! AAHHHHH SOMEBODY HELP!
If each square of the grid below is $0.5\text{ cm}$ by $0.5\text{ cm}$, how many square centimeters are in the area of the blue figure?
Answer:
8.50 cm²
Step-by-step explanation:
The dimension of each square is given as 0.5cm by 0.5cm
The area of the a square is, a²
Where, a = side length
Area of each square = 0.5² = 0.25cm
The number of blue colored squares = 34
The total area of the blue colored squares is :
34 * 0.25 = 8.50cm²
Question:
which is a y-intercept of the graphed function?
Answers:
A. (-9,0)
B. (-3,0)
C. (0,-9)
D. (0,-3)
Answer:
(0, -9)
Step-by-step explanation:
The y intercept is the y value when x =0
(0, -9)
express the ratio as a fraction in it's lowest terms.3kg to 800g
Answer:
15 / 4
Step-by-step explanation:
1 kg = 1000 g
3 kg
= 3 x 1000
= 3000 g
3kg to 800g
= 3kg : 800g
= 3000 : 800
= 30 : 8
= 30 / 8
= 15 / 4
15/4 is the fraction representing the ratio of 3 kilograms to 800 grams.
To express the ratio of 3 kilograms to 800 grams as a fraction in its lowest terms.
we need to convert both the quantities to the same units. Since 1 kg is equal to 1000 g, we can convert 3 kg to grams as follows:
3 kg = 3 * 1000 g = 3000 g
Now, we have the quantities in the same unit, and the ratio becomes:
3000 g to 800 g
To express this ratio as a fraction, we place the quantities over each other:
3000 g
-------
800 g
Now, to simplify the fraction to its lowest terms, we find the greatest common divisor (GCD) of the two numbers (3000 and 800) and divide both the numerator and denominator by this GCD.
The GCD of 3000 and 800 is 200, so dividing both by 200 gives us:
3000 ÷ 200 = 15
800 ÷ 200 = 4
Therefore, the ratio 3 kg to 800 g expressed as a fraction in its lowest terms is 15/4.
In summary, we first converted the units to the same (grams) to make the ratio easier to handle. Then, we represented the ratio as a fraction and simplified it to its lowest terms using the GCD method. The final answer, 15/4, is the fraction representing the ratio of 3 kilograms to 800 grams.
To know more about Fraction here
https://brainly.com/question/32865816
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Please help !!!! will mark brainliest !!
Answer:
the first one
Step-by-step explanation:
Not sure what to pick
Answer:
option d is correct answer
Answer:
Step-by-step explanation:
D looks good
A card is drawn from a well shuffled pack of 52 cards . find the probability of '2' of spades
Answer:
[tex] \frac{1}{52} [/tex]Step-by-step explanation:
Given,
Total no. of cards = 52
No. of 2 of spades cards = 1
Therefore,
Probability of getting 2 of spades
[tex] = \frac{no. \: of \: required \: outcomes}{total \: outcomes} [/tex]
[tex] = \frac{1}{52} (ans)[/tex]
Let f(x) = 2x + 8, g(x) = x² + 2x – 8, and h(x)
Perform the indicated operation. (Simplify as far as possible.)
(g - f)(2) =
Suppose that two balanced, six sided dice are tossed repeatedly and the sum of the two uppermost faces is determined on each toss. (a) What is the probability that we obtain a sum of 3 before we obtain a sum of 7
Answer:
[tex]\frac{(2/36)}{(1-(28/36))} = 1/4[/tex]
Step-by-step explanation:
what are the following proof triangle LMN equals triangle OPQ
Answer:
D. SSS
Step-by-step explanation:
Was given to us that the corresponding sides are congruent so is SSS.
Side Side Side Theorem tells us that if am the sides of a triangle are having the same measurement with the corresponding sides of another triangle then the two triangles are congruent.
Determine if each statement is always, sometimes, or never true.
Parallel lines are
coplanar.
Perpendicular lines are
coplanar.
Distance around an unmarked circle can
be measured
Answer:
1) Parallel lines are "ALWAYS"
coplanar.
2) Perpendicular lines ARE "ALWAYS"
coplanar.
3) Distance around an unmarked circle CAN "NEVER" be measured
Step-by-step explanation:
1) Coplanar means lines that lie in the same plane. Now, for a line to be parallel to another line, it must lie in the same plane as the other line otherwise it is no longer a parallel line. Thus, parallel lines are always Coplanar.
2) similar to point 1 above, perpendicular lines are Coplanar. This is because perpendicular lines intersect each other at right angles and it means they must exist in the same plane for that to happen. Thus, they are always Coplanar.
3) to have the distance, we need to have the circle marked out. Because it is from the marked out circle that we can measure radius, diameter and find other distances around the circle. Thus, distance around an unmarked circle can never be measured.
Kim ran 9/10 of a mile. Adrian ran 3/5 of a mile Adrian claims that Kim ran 1 3/10 times farther than him Kim says that she actually ran 1/2 times farther than Adrian who is correct
9514 1404 393
Answer:
Kim
Step-by-step explanation:
The ratio of Kim's distance to Adrian's distance is ...
(9/10)/(3/5) = (9/10)/(6/10) = 9/6 = 3/2 = 1.5
__
You need to be very careful with the wording here. Kim ran 1 1/2 times as far as Adrian. That is, she ran Adrian's distance plus 1/2 Adrian's distance.
If we take the wording "1/2 times farther" to mean that 1/2 of Adrian's distance is added to Adrian's distance, then Kim is correct.
_____
In many Algebra problems, you will see the wording "k times farther" to mean the distance is multiplied by k. If that interpretation is used here, neither claim is correct, as Kim's distance is 1 1/2 times farther than Adrian's.
On the other hand, if the value of "k" is expressed as a percentage, the interpretation usually intended is that that percentage of the original distance is added to the original distance. Using this interpretation, Kim's distance is 50% farther than Adrian's. (Note the word "times" is missing here.)
__
Since Adrian ran 1 5/10 the distance Kim ran, Adrian's claim is incorrect regardless of the interpretation. If you require one of the two to be correct, then Kim is.
Please help with this
Answer:
i think you answer is correct as it has to be less that 64 yards since it is not on a big slant. using reference from the first section forty yards is not as big as the sectuon you are looking for therefore using estimation, the answer is most likely b 53 and 1 thirds
What is the measure of L?
A. 390
B. 25°
C. Cannot be determined
D. 32°
Answer:
∠L = 25°
Step-by-step explanation:
Two sides are equal. so , it is an isosceles triangle.
Angles opposite to equal sides are equal.
∠L = 25
Use the graph of y=-2(x-3)^2+2 to find the vertex. Decide whether the vertex is a maximum or a minimum point.
Answer: B. Vertex is a maximum point at (3, 2)
The vertex is the point at the peak of the graph: (3, 2)Since the graph opens downward, it's the maximum pointWhen the Bucks play Chiefs at football, the probability that the Chiefs, on present form, will win is 0.56. In a competition, these teams are to play two more pgames. If Swallows beats Bucks in at least4one of these games, they will win the competition, otherwise Bucks will win the trophy. NB: Round off to 2 decimal places. a. The probability that Swallows will win the trophy is [a] probability that Rucks will win the trophy is
Answer:
The probability that Swallows will win the trophy is 0.8064
The probability that Rucks will win the trophy is 0.1936
Step-by-step explanation:
For each game, there are only two possible outcomes. Either the Swallows win, or they do not. The probability of them winning a game is independent of any other game, which means that the binomial probability 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 [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]
And p is the probability of X happening.
Probability the Swallows wins is 0.56
This means that [tex]p = 0.56[/tex]
2 games:
This means that [tex]n = 2[/tex]
The probability that Swallows will win the trophy is
Probability they win at least one game, so:
[tex]P(X \geq 1) = 1 - P(X = 0)[/tex]
In which
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 0) = C_{2,0}.(0.56)^{0}.(0.44)^{2} = 0.1936[/tex]
Then
[tex]P(X \geq 1) = 1 - 0.1936 = 0.8064[/tex]
0.8064 = 80.64% probability the Swallows win the trophy and 0.1936 probability that the Rucks win the trophy.
Suppose that the IQ of a randomly selected student from a university is normal with mean 115 and standard deviation 25. Determine the interval of values that is centered at the mean and for which 50% of the students have IQ's in that interval.
Answer:
The interval is [98,132]
Step-by-step explanation:
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.
Normal with mean 115 and standard deviation 25.
This means that [tex]\mu = 115, \sigma = 25[/tex]
Determine the interval of values that is centered at the mean and for which 50% of the students have IQ's in that interval.
Between the 50 - (50/2) = 25th percentile and the 50 + (50/2) = 75th percentile.
25th percentile:
X when Z has a p-value of 0.25, so X when Z = -0.675.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]-0.675 = \frac{X - 115}{25}[/tex]
[tex]X - 115 = -0.675*25[/tex]
[tex]X = 98[/tex]
75th percentile:
X when Z has a p-value of 0.75, so X when Z = 0.675.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]0.675 = \frac{X - 115}{25}[/tex]
[tex]X - 115 = 0.675*25[/tex]
[tex]X = 132[/tex]
The interval is [98,132]
HELP ASAP I WILL GIVE BRAINLIST
If sin ∅ = -sqrt{3} OVER 2 and π < ∅ < 3π OVER 2, what are the values of cos ∅ and tan ∅? What is ∅ in degrees and radians? Be sure to show and explain all work.
Step-by-step explanation:
sin ∅ = -(√3)/2
Note that
cos²∅ + sin²∅ = 1
cos²∅ = 1 - sin²∅
= 1 - (-√3 / 2)²
= 1 - (-√3)²/ 2²
= 1 - 3/4
= 1/4
cos²∅ = 1/4
Taking square root of both sides
cos∅ = 1/2
Note that tan∅ = sin∅/cos∅
therefore, tan∅ = -(√3)/2 ÷ 1/2
= -(√3)/2 × 2/1
= -√3
tan∅ = -√3
Since sin∅ = -√3 /2
Then ∅ = -60⁰
The value of ∅ for the given range (third quadrant) is 240⁰.
NB: sin∅ = sin(180-∅)
Also, since 180⁰ is π radians, then ∅ = 4π/3
A bacteria culture initially contains 100 cells and grows at a rate proportional to its size. After an hour the population has increased to 310.
(a) Find an expression for the number of bacteria after
hours.
(b) Find the number of bacteria after 3 hours.
(c) Find the rate of growth after 3 hours.
(d) When will the population reach 10,000?
Answer:
a) The expression for the number of bacteria is [tex]P(t) = 100\cdot e^{1.131\cdot t}[/tex].
b) There are 2975 bacteria after 3 hours.
c) The rate of growth after 3 hours is about 3365.3 bacteria per hour.
d) A population of 10,000 will be reached after 4.072 hours.
Step-by-step explanation:
a) The population growth of the bacteria culture is described by this ordinary differential equation:
[tex]\frac{dP}{dt} = k\cdot P[/tex] (1)
Where:
[tex]k[/tex] - Rate of proportionality, in [tex]\frac{1}{h}[/tex].
[tex]P[/tex] - Population of the bacteria culture, no unit.
[tex]t[/tex] - Time, in hours.
The solution of this differential equation is:
[tex]P(t) = P_{o}\cdot e^{k\cdot t}[/tex] (2)
Where:
[tex]P_{o}[/tex] - Initial population, no unit.
[tex]P(t)[/tex] - Current population, no unit.
If we know that [tex]P_{o} = 100[/tex], [tex]t = 1\,h[/tex] and [tex]P(t) = 310[/tex], then the rate of proportionality is:
[tex]P(t) = P_{o}\cdot e^{k\cdot t}[/tex]
[tex]\frac{P(t)}{P_{o}} = e^{k\cdot t}[/tex]
[tex]k\cdot t = \ln \frac{P(t)}{P_{o}}[/tex]
[tex]k = \frac{1}{t}\cdot \ln \frac{P(t)}{P_{o}}[/tex]
[tex]k = \frac{1}{1}\cdot \ln \frac{310}{100}[/tex]
[tex]k\approx 1.131\,\frac{1}{h}[/tex]
Hence, the expression for the number of bacteria is [tex]P(t) = 100\cdot e^{1.131\cdot t}[/tex].
b) If we know that [tex]t = 3\,h[/tex], then the number of bacteria is:
[tex]P(t) = 100\cdot e^{1.131\cdot t}[/tex]
[tex]P(3) = 100\cdot e^{1.131\cdot (3)}[/tex]
[tex]P(3) \approx 2975.508[/tex]
There are 2975 bacteria after 3 hours.
c) The rate of growth of the population is represented by (1):
[tex]\frac{dP}{dt} = k\cdot P[/tex]
If we know that [tex]k\approx 1.131\,\frac{1}{h}[/tex] and [tex]P \approx 2975.508[/tex], then the rate of growth after 3 hours:
[tex]\frac{dP}{dt} = \left(1.131\,\frac{1}{h} \right)\cdot (2975.508)[/tex]
[tex]\frac{dP}{dt} = 3365.3\,\frac{1}{h}[/tex]
The rate of growth after 3 hours is about 3365.3 bacteria per hour.
d) If we know that [tex]P(t) = 10000[/tex], then the time associated with the size of the bacteria culture is:
[tex]P(t) = 100\cdot e^{1.131\cdot t}[/tex]
[tex]10000 = 100\cdot e^{1.131\cdot t}[/tex]
[tex]100 = e^{1.131\cdot t}[/tex]
[tex]\ln 100 = 1.131\cdot t[/tex]
[tex]t = \frac{\ln 100}{1.131}[/tex]
[tex]t \approx 4.072\,h[/tex]
A population of 10,000 will be reached after 4.072 hours.