Answer:
.0668
Step-by-step explanation:
Formula:
z=(x-average)/standard deviation
(2.5-2.8)/.2= -1.5
Go to a ztable and find the value for 1.5 (.9332) and take the compliment of this (we can do this because the normal distribution is symmetrical)
1-.9332= .0668
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.
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A geologist has collected 5 specimens of basaltic rock and 7 specimens of granite. The geologist instructs a laboratory assistant to randomly select 9 of the specimens for analysis.
Let X= the number of granite specimens selected for analysis.
Note: Take 10 decimal places after the ".", if the answer is a fraction, enter the fraction (a/b). Use a period (.) not a comma (,) for decimals.
a) Compute EX = ?; Var(X) = ?
b) Compute P(X<6) = ?
c) What is the probability that all specimens of one of the two types of rock are selected for analysis?
P(all specimens of one of the two types of rock are selected for analysis) = ?
The rocks are chosen without replacement, which means that the hypergeometric distribution is used to solve this question. First we get the parameters, and then we answer the questions. From this, we get that:
[tex]E(X) = 5.25, Var(X) = 0.5966[/tex]P(X < 6) = 0.9545P(all specimens of one of the two types of rock are selected for analysis) = 0.2046.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]
The mean and the variance are:
[tex]\mu = \frac{nk}{N}[/tex]
[tex]\sigma^2 = \frac{nk(N-k)(N-n)}{N^2(N-1)}[/tex]
We have that:
5 + 7 = 12 rocks, which means that [tex]N = 12[/tex]
9 are chosen, which means that [tex]n = 9[/tex]
7 are granite, which means that [tex]k = 7[/tex]
Question a:
[tex]E(X) = \mu = \frac{9\times7}{12} = 5.25[/tex]
[tex]Var(X) = \sigma^2 = \frac{9\times7(12-7)(12-9)}{12^2(12-1)} = 0.5966[/tex]
Thus:
[tex]E(X) = 5.25, Var(X) = 0.5966[/tex]
Question b:
Since there are only 5 specimens of basaltic rock, at least 9 - 5 = 4 specimens of granite are needed, which means that:
[tex]P(X < 6) = P(X = 4) + P(X = 5) + P(X = 6)[/tex]
In which
[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}[/tex]
[tex]P(X = 4) = h(4,12,9,7) = \frac{C_{7,4}*C_{5,5}}{C_{12,9}} = 0.1591[/tex]
[tex]P(X = 5) = h(5,12,9,7) = \frac{C_{7,5}*C_{5,4}}{C_{12,9}} = 0.4773[/tex]
[tex]P(X = 6) = h(6,12,9,7) = \frac{C_{7,6}*C_{5,3}}{C_{12,9}} = 0.3181[/tex]
Thus
[tex]P(X < 6) = P(X = 4) + P(X = 5) + P(X = 6) = 0.1591 + 0.4773 + 0.3181 = 0.9545[/tex]
So P(X < 6) = 0.9545.
Question c:
5 of basaltic and 4 of granite: 0.1591 probability.
7 of granite is P(X = 7), in which
[tex]P(X = 7) = h(7,12,9,7) = \frac{C_{7,7}*C_{5,2}}{C_{12,9}} = 0.0455[/tex]
0.1591 + 0.0455 = 0.2046, thus:
P(all specimens of one of the two types of rock are selected for analysis) = 0.2046.
A similar question is found at https://brainly.com/question/24008577
Find the length of AC on this triangle
Answer:
A
Step-by-step explanation:
Using the tangent ratio in the right triangle
tan12° = [tex]\frac{opposite}{adjacent}[/tex] = [tex]\frac{AC}{BC}[/tex] = [tex]\frac{AC}{44}[/tex] ( multiply both sides by 44 )
44 × tan12° = AC , then
AC ≈ 9.35 ( to 2 dec. places )
Complete the proof and rewrite the statements.
Given :
ABC is an isosceles triangle in which AC = BC
CD ⊥ AB
Prove : AD = BD
Statement Reason
i) AC = BC Given
ii) ԼCDA = _______ Right angle
iii) CD = CD Common side
iv) ΔADC ≅ Δ BDC _______ test
v) AD = BD CPCT
Answer:
Step-by-step explanation:
(ii) right angle becuase perpendicular
iv) congruent because <b=<a (opp ang in isc.tria. is equal)
since ΔADC ≅ Δ BDC, AB=BD
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
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
Ben consumes an energy drink that contains caffeine. After consuming the energy drink, the amount of caffeine in Ben's body decreases exponentially. The 10-hour decay factor for the number of mg of caffeine in Ben's body is 0.2722. What is the 5-hour growth/decay factor for the number of mg of caffeine in Ben's body
Answer:
The 5-hour decay factor for the number of mg of caffeine in Ben's body is of 0.1469.
Step-by-step explanation:
After consuming the energy drink, the amount of caffeine in Ben's body decreases exponentially.
This means that the amount of caffeine after t hours is given by:
[tex]A(t) = A(0)e^{-kt}[/tex]
In which A(0) is the initial amount and k is the decay rate, as a decimal.
The 10-hour decay factor for the number of mg of caffeine in Ben's body is 0.2722.
1 - 0.2722 = 0.7278, thus, [tex]A(10) = 0.7278A(0)[/tex]. We use this to find k.
[tex]A(t) = A(0)e^{-kt}[/tex]
[tex]0.7278A(0) = A(0)e^{-10k}[/tex]
[tex]e^{-10k} = 0.7278[/tex]
[tex]\ln{e^{-10k}} = \ln{0.7278}[/tex]
[tex]-10k = \ln{0.7278}[/tex]
[tex]k = -\frac{\ln{0.7278}}{10}[/tex]
[tex]k = 0.03177289938 [/tex]
Then
[tex]A(t) = A(0)e^{-0.03177289938t}[/tex]
What is the 5-hour growth/decay factor for the number of mg of caffeine in Ben's body?
We have to find find A(5), as a function of A(0). So
[tex]A(5) = A(0)e^{-0.03177289938*5}[/tex]
[tex]A(5) = 0.8531[/tex]
The decay factor is:
1 - 0.8531 = 0.1469
The 5-hour decay factor for the number of mg of caffeine in Ben's body is of 0.1469.
Twenty-seven minus 3/2 of a number (x) os not mpre than 36. What is the number?
Answer:
-6
Step-by-step explanation:
27-3/2x=36
53-3x=72
3x=-18
x=-6
Been stuck for 30 mins now please help !!!
Answer:
D) y = 2x + 1
Step-by-step explanation:
A group of friends will go on a weekend camping trip and split the cost of gas
equally. The cost that each person will pay for gas is inversely proportional to the
number of people who go on the trip. If four friends go on the trip, each person pays
$23 for gas. Write an equation that describes the relationship between cost (c) that
each person pays for gas, and the number of people on the trip (n).
C = 92/n
C= n/0.17
C = 5.75n
C = 5.75/n
9514 1404 393
Answer:
(a) C = 92/n
Step-by-step explanation:
The "inversely proportional" relation is represented by the equation ...
C = k/n
The value of k can be found from the given values of C and n.
23 = k/4
23×4 = k = 92
Then the relationship is ...
C = 92/n
1.8 times 15.42 please this question has me stuck
Answer:
27.756
Step-by-step explanation:
1) Move all the decimal points to the right and do the multiplication
18 * 1524 = 27756
1.8 to 19 = one move
15.42 to 1542 = two moves
total three decimal point shifts
2) count the number (total) that you moved the decimal points
3) starting from the right move the decimal point that many times to the LEFT in for the answer
27.756
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:
15 = g + 8 pllllllllllssssss help
Please help me I need it!
F(x) = x +3; G(x) = 2x^2 -4 Find (f*g)(x)
9514 1404 393
Answer:
(f·g)(x) = 2x^3 +6x^2 -4x -12
Step-by-step explanation:
The distributive property is used to find the expanded form of the product.
(f·g)(x) = f(x)·g(x) = (x +3)(2x^2 -4) = x(2x^2 -4) +3(2x^2 -4)
= 2x^3 -4x +6x^2 -12
(f·g)(x) = 2x^3 +6x^2 -4x -12
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
help please! I need the answer quickly! thank you!
Answer:
B) 1 unit to the left
Step-by-step explanation:
What is the height of a room which is 8m long, 6m wide and contains 144 meters cube of air?
Let f(x) = 2x + 2. Solve f−1(x) when x = 4. (1 point)
Answer:
1
Step-by-step explanation:
First, find the inverse of the original function.
x = 2y + 2
x-2/2
Second, substitute x with 4 and solve.
4-2/2
2/2
1
Best of Luck!
If f(x) = 2x + 2 is invertible, then its inverse is another function f ⁻¹(x) such that
f(f ⁻¹(x)) = 2 f ⁻¹(x) + 2 = x
Solve for f ⁻¹(x) :
2 f ⁻¹(x) + 2 = x
2 f ⁻¹(x) = x - 2
f ⁻¹(x) = (x - 2)/2 = x/2 - 1
Then when x = 4, we have f ⁻¹ (4) = 4/2 - 1 = 2 - 1 = 1.
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.
There is only 3/4 cup of ice cream left. If 3 friends share the ice cream equally, how much ice cream will they each get?
Answer:
1/4 cup each
Step-by-step explanation:
Take the amount of ice cream and divide by 3
3/4÷ 3
Copy dot flip
3/4 * 1/3
Rewriting
3/3 * 1/4
1/4 cup each
(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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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?
8. Add.
445,976 + 37,415 =
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!
Q-21: The regions of inequalities are also called:
A) Planes B) Lines C) Half planes D) None of these
Answer:
D ) none of these .. i think this help you
how many years will it take for a sum of money to double at 10% compounded annually
Answer:
t=7.27 years
Step-by-step explanation:
Let the money be p and t will be the number of years that will be needed for the money to get double.
ATQ, 2p=p*(1+0.1)^t
2=(1.1)^t
log(2)/log(1.1)=t, t=7.27
The equation 8(y-3)= -40 is solved in several steps below. For each step, choose the reason that best justifies it.
Addition property of Equality
Subtraction Property of Equality
Multiplication property of equality
Division property of equality
simplifying
distributive property
Answer:
Step-by-step explanation:
The steps and their reasons for the equation 8(y - 3) = - 40 are given below.
What is the solution to the equation?The allocation of weights to the important variables that produce the calculation's optimum is referred to as a direct consequence.
The equation is given below.
8(y - 3) = - 40
Steps Reason
8(y - 3) = - 40 Given
8y - 24 = - 40 Distributive property
8y - 24 + 24 = - 24 + 24 Addition Property of Equality
8y = - 16 Simplifying
8y / 8 = - 16/8 Division property of equality
y = - 2 Simplifying
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sketch the graph of y=x(x-6)^
Answer:
i have attached pic of the graph
i hope this helps you
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.
