Using the normal distribution, it is found that:
a) 4.46% of finish times was higher than 72 minutes.
b) 55.11% of finish times was between 52 and 70 minutes.
c) The 40th percentile of finish times is 52.5 minutes.
d) The 95th percentile of finish times is 71.45 minutes.
In a normal distribution 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]
It 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, which is the percentile of X.In this problem:
The mean is of 55 minutes, hence [tex]\mu = 55[/tex].The standard deviation is of 10 minutes, hence [tex]\sigma = 10[/tex]Item a:
The proportion is 1 subtracted by the p-value of Z when X = 72, hence:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{72 - 55}{10}[/tex]
[tex]Z = 1.7[/tex]
[tex]Z = 1.7[/tex] has a p-value of 0.9554
1 - 0.9554 = 0.0446
0.0446 x 100% = 4.46%
4.46% of finish times was higher than 72 minutes.
Item b:
Th proportion is the p-value of Z when X = 70 subtracted by the p-value of Z when X = 52, hence:
X = 70:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{70 - 55}{10}[/tex]
[tex]Z = 1.5[/tex]
[tex]Z = 1.5[/tex] has a p-value of 0.9332.
X = 52:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{52 - 55}{10}[/tex]
[tex]Z = -0.3[/tex]
[tex]Z = -0.3[/tex] has a p-value of 0.3821.
0.9332 - 0.3821 = 0.5511
0.5511 x 100% = 55.11%
55.11% of finish times was between 52 and 70 minutes.
Item c:
The 40th percentile is X when Z has a p-value of 0.4, so X when Z = -0.253.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]-0.253 = \frac{X - 55}{10}[/tex]
[tex]X - 55 = -0.253(10)[/tex]
[tex]X = 52.5[/tex]
The 40th percentile of finish times is 52.5 minutes.
Item d:
The 95th percentile is X when Z has a p-value of 0.95, so X when Z = 1.645.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]1.645 = \frac{X - 55}{10}[/tex]
[tex]X - 55 = 1.645(10)[/tex]
[tex]X = 71.45[/tex]
The 95th percentile of finish times is 71.45 minutes.
A similar problem is given at https://brainly.com/question/24663213
calculate the interquartile range of 45 47 48 49 50 51 52 53 60
Answer:
48
I hope it helps.
grahm's birthday Is on 26th May which day of the week Is his birthday?
Answer:
Wednesday, 2021,Thursday, 2022
HELP!! YOU'LL GET BRAINLIEST
Answer:
b = 1
Step-by-step explanation:
What is the answer to
2 3/8 - 1 5/8 =
Answer:
6/8
Step-by-step explanation:
you have to convert each fraction into an improper. because the denominators are already the same, you dont have to worry. once you have it as an impropper, you can now subtract it. 19/8 - 13/8 = 6/8
reduce if you can
Find the value for x.
Answer:
x = 21Step-by-step explanation:
5x - 12 = 3x + 30
5x - 3x = 30 + 12
2x = 42
x = 21
---------------------
check
5 * 21 - 12 = 3 * 21 + 30
93 = 93
the answer is good
which histogram helps best predict how much time until the next customer comes into the Clothes Shoppe.
A survey concluded that 5 out of every 6 teachers
drink at least one cup of coffee in the morning
before school. If Lubbock Middle School has 78
teachers, approximately how many teachers
would you predict drink at least one cup of coffee?
Answer:
5+6= 11
78-11= 67
That is the final answer
BRAINLIEST TO CORRECT PLEASE HURRY
Answer:
-32
Step-by-step explanation:
Graph the image of this figure after a dilation with a scale factor of 12centered at the origin.
Use the polygon tool to graph the dilated figure.
Answer:
1.(-4,2)
2.(2,4)
3.(-2,8)
Answer:
(1,2) (0,4) (-4,2)
Step-by-step explanation:
took the quiz and got it right.
What is the nth term of each linear pattern?
a) 5.4, 8.4, 11.4, 14.4, 17.4...
b) 85, 80, 75, 70...
c) 38 1/2, 43 1/2, 48 1/2, 53 1/2, 58 1/2
Can someone help? anyone?
Answer:
The right answer is letter C.
Step-by-step explanation:
I hope it's help
have a nice day and night
Solve for z.
57 = –10z +7
Answer:
z = -5
Step-by-step explanation:
Hi there!
We are given the equation 57 = -10z + 7, and we want to solve for z
In order to solve an equation for a variable, we want to isolate that variable on one side; in other words, we want just z on one side of the equation.
So that means that we'll need to get rid of everything else that's also on the right side. That starts with subtracting 7 from both sides:
57 = -10z + 7
-7 -7
_____________
50 = -10z
Now on the right side, there aren't any other extra terms, but remember: we want just z (also written as 1z, with the coefficient of 1), not z written with a coefficient of -10
If you divide a number by itself, the result is 1. For example. [tex]\frac{3}{3}[/tex]= 1. So in order to get a coefficient of 1, let's divide both sides by -10
[tex]\frac{50}{-10} = \frac{-10z}{-10}[/tex]
Divide, and cancel:
The zeros cancel out, leaving the equation as:
[tex]\frac{5}{-1} = \frac{-1z}{-1}[/tex]
Dividing a number by -1 is pretty much the same as multiplying a number by -1; it simply changes the sign of the number
So 5/-1 will become -5, while -1z/-1 will become 1z, or z
Hence:
-5 = z, or written the other way: z = -5
We found z.
Hope this helps!
7. Juanita is painting her house. She can either
buy Brand A paint and a paint roller tray or
a
Brand B paint and a grid for the paint roller. For
how many gallons of paint would the price for
both options be the same? If Juanita needs 15
gallons of paint, which is the better option?
Step-by-step explanation:
brand a is better option why because we have paint and paint roller
If you buy 1 gallon can of paint both brands will cost $30 and brand B paint is a better option because it costs less.
What is the equation?An equation is a statement that two expressions, which include variables and/or numbers, are equal. In essence, equations are questions, and efforts to systematically find solutions to these questions have been the driving forces behind the creation of mathematics.
Suppose y is the total cost and x is the gallons cases,
The equations according to the given condition are,
y = 27 x + 3
y = 2x +5
The values obtained after solving the above equation will be (1,30). As a result, 1 gallon of paint cost you $ 30.
For condition 2 Juanita needs 15 gallons of paint, x =15
For A, y = 408
For B, y = 380
The brands A and B cost $408 and $380.So the brand costs Juanita more.
Thus, if you buy 1 gallon can of paint both brands will cost $30 and brand B paint is a better option because it costs less.
Learn more about the equation here,
https://brainly.com/question/10413253
#SPJ5
1.3.2 checkup - lessons learned
2. What is the slope of the line represented by the table of values below? How do you know?
Answer:
y=2/3x-4
Step-by-step explanation:
we can see that x goes up 1 for every 1.5y and if we start y at 0 x starts at -4 so if y is one than x has to be 2/3-4 becuase it is -4 + 2/3 for every 1 y goes up or one for every 1.5 y goes up. hope this answer was helpful.
Match to the other shape
Answer:
wheres the picture?
Step-by-step explanation:
HELPPP LAST ATTEMPT!!
Which of the accounts below are considered accrued expenses?
Answer:
Accrued expenses are those liabilities that have built up over time and are due to be paid. Accrued expenses are considered to be current liabilities because the payment is usually due within one year of the date of the transaction. Accounts payable are current liabilities that will be paid in the near future.
Answer:
Wages expense, Interest expense
Step-by-step explanation:
What are the answers pls I don’t get it
Answer:
answers are (1+0.13)x and 1.13x
Step-by-step explanation:
i did this one last year and got it right :)
Write 5 • 5 • 5 • 5 • 5 • 5 • 5 using an exponent.
Answer:
5^6
Step-by-step explanation:
5 was multiplied repeatedly 6 times, so it's 5 to the power of 6
Answer:
5 to the power of 6 or 5^6
Step-by-step explanation:
Q2). Let A={1,2,3,4} B={a,b,c} which of the following are relation from B to A?
(i) {(c,a) (c,b) (c,1)}
(ii) {(c,4) (b,3) (c.2)}
Step-by-step explanation:
Given sets are :
A = {1,2,3,4} and B = {a,b,c}
(i)
What is the solution of this system of equations?
x + 3y = 7
3x +2y = 0
A. (3,2)
B. (-2,3)
C. (2, -3)
D. (-3,2)
E. (-2,-3)
Answer:
B. (-2,3)
Explanation:
First, we'll turn both lines to slope-intercept form:
x + 3y = 7
Subtract x on both sides to get 3y = -x + 7, then divide 3 on both sides to get y = -1/3x + 7/3.
3x + 2y = 0
Subtract 3x on both sides to get 2y = -3x, then divide 2 on both sides to get y = -3/2x.
Now you can graph (I did it for you above⤴⤴⤴).
Hope this helps you :)
In the final exams, 40% of the students failed chemistry, 25% failed physics, and 19% failed both chemistry and physics. What is the probability that a randomly selected student failed physics given that he passed chemistry?
I have answered the question in the image below, but I would like to know if it is correct. If it is not, please include an explanation of why, as well as the step by step to get the correct answer
Answer:
10%
Step-by-step explanation:
If 40% failed chemistry then 60% passed chemistry.
If 19% failed both chemistry and physics, and 25% failed physics, then 6% passed chemistry and failed physics.
If we let p' represent failing physics and c represent passing chemistry, then ...
P(p'|c) = P(p'c)/P(c)
P(p'|c) = 6%/60% = 0.10 = 10%
If the randomly chosen student passed chemistry, the probability is 10% that he failed physics.
__
Your answer is correct.
To solve this problem, we can use conditional probability.
Let's assume that there were 100 students in the final exam.
According to the problem, 40% of the students failed chemistry, which means that 60% of the students passed chemistry.
We can see that 25% of the students failed physics, and 19% of the students failed both chemistry and physics.To find the probability that a randomly selected student failed physics given that he passed chemistry, we need to use Bayes' theorem:
[tex]\sf P(Failed\: Physics | Passed\: Chemistry) = \dfrac{P(Failed\: Physics\: and\: Passed\: Chemistry)}{ P(Passed\: Chemistry)}[/tex]
We already know that P(Failed Physics and Passed Chemistry) = 6 students (from the Venn diagram), and P(Passed Chemistry) = 60 students (since 60% of the students passed chemistry).
Therefore,
[tex]\sf P(Failed\: Physics | Passed\: Chemistry) = \dfrac{6}{60} = 0.1\: or\: 10\%[/tex]
So the probability that a randomly selected student failed physics given that he passed chemistry is 10%.
Which table represents y as a function of x?
X
1
2
0
0
1
2
3
3
X
-1
-1
o
2
1
0
2
3
X
V
1
10
2
3
0
1
2
3
x
V
-1
-1
0
-1
Answer:
reduce
Step-by-step explanation:
become it is un solvef
Identify the initial amount a and the rate of growth r (as a percent) of the exponential function f(t) = 1500(1.074)t. Evaluate the
function when t=5. Round your answer to the nearest tenth.
A=
R=%
When t=5, f(5)=
The initial amount is the first number = 1500
Rate of growth is inside the parentheses and is added to 1, the rate of growth is 7.4%
Replace t with 5 and solve
1500(1.074) ^5 = $2143.45
Answer:
The growth rate is 7.4% and the initial amount is 1500. The answer when t=5 is 2143.45.
Step-by-step explanation:
Assuming this is actually supposed to be written as 1500*(1.074)^t, then this equation follows the standard growth form y = A(1+r)^t where A represents the initial amount, r represents the rate as a decimal, and t represents time. This means that 1500 (A) would be the initial amount, and if you subtract 1 from what's inside the paratheses, you will get the r rate as a decimal. To get this as a percent, simply multiply it by 100, so you will get 7.4% as your growth rate.
To find what the answer would be when t = 5, just plug in 5 for the value of t in the equation.
f(5) = 1500*(1.074^5)
f(5) = 1500*(1.42896)
f(5) = 2143.45
What is Two-thirds divided by one-sixth?
An area model with 4 shaded parts and 2 unshaded parts. The shaded parts are labeled two-thirds.
2
3
4
6
Answer: 4
Step-by-step explanation:
So, what I do to divide fractions is to turn them into reciprocals, which means changing it into a multiplication problem and turning the second fraction upside down. So, [tex]\frac{2}{3}[/tex] x [tex]\frac{6}{1}[/tex]. We multiply across, so 2 x 6 is 12, and 3 x 1 is 3, which gets us to [tex]\frac{12}{3}[/tex]. Since this is an improper fraction, we can simplify by dividing 12 by 3 to get 4. Hope this helps! :)
Answer:
4 (C) hope this helps!!
BYEEEEEEEEE!
Solve ^3/x^2-8=2 pls help
Answer:
its the first one
Step-by-step explanation:
Given the definitions of f(x) and g(x) below, find the value of g(f(-3)). f(x) = 5x + 11 g(x) = x2 + 4x – 11
Answer:
g(f(-3)) = -11
Step-by-step explanation:
First, we evaluate f(-3) and then plug that value into g(x) for x:
f(x) = 5x + 11
f(-3) = 5(-3) + 11 = -15 + 11 = -4
Therefore:
g(f(-3)) = (-4)^2 + 4(-4) - 11 = 16 - 16 - 11 = 0 - 11 = -11
Answer: -11
Step-by-step explanation:
Find the value of g(f(-3)) given the two equations:
f(x) = 5x + 11
g(x) = x² + 4x - 11
Plug -3 into equation f(x).
f(-3) = 5(-3) + 11
Solve for f(x).
-4 = f(-3)
Plug -4 into the equation of g(x).
g(-4) = (-4)² + 4(-4) - 11
Solve for g(x).
g(-4) = (16) + (-16) - 11
g(-4) = -11
The value of g(f(-3)) is -11.
A pennant flag that is 2 inches high with a base of 1.5 inches has an area of 1.5 square inches. The
area of a triangle varies jointly with the base and height. Find the area of a flag whose base
measures 2 inches and height is 2.5 inches.
Answer:
2.5 sq. inches
Step-by-step explanation:
Explanation is given in the pic attached.
Area of triangle= 1/2* base* height
Hope this helps!
The area of the flag when the base is 2 inches and the height is 2.5 inches is 2.5 square inches
From the question, we understand that the area (A) of the flag varies jointly with the base (B) and the height (H)
This variation is represented as:
[tex]\mathbf{A\ \alpha\ B \times H}[/tex]
So, we have:
[tex]\mathbf{A\ \alpha\ BH}[/tex]
Express as an equation
[tex]\mathbf{A\ =k BH}[/tex]
When the area is 1.5 square inches, the base is 1.5 inches and the height is 2 inches, we have:
[tex]\mathbf{A\ =k BH}[/tex]
This gives
[tex]\mathbf{1.5\ =k \times 1.5 \times 2}[/tex]
[tex]\mathbf{1.5\ =k \times 3}[/tex]
Divide both sides by 3
[tex]\mathbf{\frac 12 =k }[/tex]
Rewrite as:
[tex]\mathbf{k = \frac 12}[/tex]
When the base is 2 inches and the height is 2.5 inches, we have:
[tex]\mathbf{A\ =k BH}[/tex]
This gives
[tex]\mathbf{A = \frac 12 \times 2 \times 2.5}[/tex]
[tex]\mathbf{A = 2.5}[/tex]
Hence, the area of the flag is 2.5 square inches
Read more about variations at:
https://brainly.com/question/14251450
(?)(3x — 2)= 24x^2 — 16x
[tex]\boxed{?}(3x-2)=24x^2-16x\implies \boxed{?}=\cfrac{24x^2-16x}{3x-2}\\\\\\\boxed{?}=\cfrac{\stackrel{\textit{common factoring}}{8x~~\begin{matrix} (3x-2) \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~}}{~~\begin{matrix} 3x-2 \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~}\implies \boxed{?}=8x[/tex]
An indoor track is made up of a rectangular region with two semi-circles at the ends. The distance around the track is 400 meters. What dimensions for the rectangular region maximize the area of the rectangular region?
Answer:
width of rectangle = 2R = (200/π) = 400/π meters
length of rectangle = 400 - π(200/π) = 400 - 200 = 200 meters
Step-by-step explanation:
The distance around the track (400 m) has two parts: one is the circumference of the circle and the other is twice the length of the rectangle.
Let L represent the length of the rectangle, and R the radius of one of the circular ends. Then the length of the track (the distance around it) is:
Total = circumference of the circle + twice the length of the rectangle, or
= 2πR + 2L = 400 (meters)
This equation is a 'constraint.' It simplifies to πR + L = 400. This equation can be solved for R if we wish to find L first, or for L if we wish to find R first. Solving for L, we get L = 400 - πR.
We wish to maximize the area of the rectangular region. That area is represented by A = L·W, which is equivalent here to A = L·2R = 2RL. We are to maximize this area by finding the correct R and L values.
We have already solved the constraint equation for L: L = 400 - πR. We can substitute this 400 - πR for L in
the area formula given above: A = L·2R = 2RL = 2R)(400 - πR). This product has the form of a quadratic: A = 800R - 2πR². Because the coefficient of R² is negative, the graph of this parabola opens down. We need to find the vertex of this parabola to obtain the value of R that maximizes the area of the rectangle:
-b ± √(b² - 4ac)
Using the quadratic formula, we get R = ------------------------
2a
-800 ± √(6400 - 4(0)) -1600
or, in this particular case, R = ------------------------------------- = ---------------
2(-2π)
-800
or R = ----------- = 200/π
-4π
and so L = 400 - πR (see work done above)
These are the dimensions that result in max area of the rectangle:
width of rectangle = 2R = (200/π) = 400/π meters
length of rectangle = 400 - π(200/π) = 400 - 200 = 200 meters
