Answer:
Step-by-step explanation:
Hello!
There are two values of n in the text, I'll use the one that appears in all the questions.
The variable of interest is
X: pollutants found in waterways near large cities. (ppm)
This variable has a normal distribution with parameters μ= 9ppm and σ= 1.5ppm
1) X~N(μ;σ²)
X~N(9;2.25)
2) The distribution of the sample mean is X~N(μ;σ²/n)
σ²/n= 2.25/37= 0.06
X~N(9;0.06)
3) P(X>9.6)
To calculate this probability you have to use the standard normal distribution. Using the population parameters, you can calculate the corresponding Z value:
Z= (X-μ)/σ= (9.6-9)/1.5= 0.4
P(Z>0.4)= 1-P(Z≤0.4)= 1 - 0.65542= 0.34458
The probability of selecting a city at random and finding 9.6ppm pollutants.
4) In this item, instead of calculating the probability of one value of the variable you have to calculate the probability of the sample average taking a determined value. Because of this, you have to work using the distribution of the sample mean, instead of the distribution of the variable.
P(X[bar]>9.6)
Z= (X[bar]-μ)/(σ/√n)= (9.6-9)/√0.06= 2.45
P(Z>2.45)= 1 - P(Z≤2.45)= 1 - 0.99286= 0.00714
5) The assumption of a normal distribution is not necessary for item 4. Since the sample size is large enough (greater than 30) you can apply the central limit theorem and approximate the distribution of the sample mean to normal, regarding the distribution of the original variable.
6)
In this case, you have to work starting with the standard normal distribution and then "translate" the Z values into values of the average amount of pollutants.
The first quartile divides the bottom 25% of the distribution from the top 75%, symbolically:
P(Z≤z₁)= 0.25
z₁= -0.674
z₁= (X[bar]-μ)/(σ/√n)
z₁*(√n/σ)=X[bar]-μ
X[bar]=z₁*(√n/σ)+μ
X[bar]=(-0.674)*(√37/1.5)+9= 6.27ppm
The third quartile divides the bottom 75% of the distribution from the top 25%, symbolically:
P(Z≤z₂)= 0.75
z₂= 0.674
z₂= (X[bar]-μ)/(σ/√n)
z₂*(√n/σ)=X[bar]-μ
X[bar]=z₂*(√n/σ)+μ
X[bar]=(0.674)*(√37/1.5)+9= 11.7.3ppm
IQR= Q₃-Q₁= 11.73-6.27= 5.46ppm
I hope this helps!
What’s the correct answer for this?
Answer:
E:
Step-by-step explanation:
The equation of circles is
(x-a)²+(y-b)²=r²
Where
Center = (a,b) = (-6,-3) and r = 12
Now
The equation becomes
(x+6)²+(x+3)²=144
Question 1 of 20 :
Select the best answer for the question.
1. Divide7/15 by 3/5
OA%
O B./25
O c. 75/21
O D.21/75
Answer:
7/9
Step-by-step explanation:
7/15 ÷ 3/5
Copy dot flip
7/15 * 5/3
7/3 * 5/15
7/3 * 1/3
7/9
Please everyone help me!
Answer:g=0 is not the solution
Step-byd-step explanation:
-1 1/2 is a negative number and 0 is not negative
Answer:
g=0
Step-by-step explanation:
happy to help ya :)
4. In the Department of Natural Sciences, 14 faculty members have a PhD, and 30 faculty
members do not have a PhD. In the Department, the number of female faculty who do not
have a PhD is 10 more than the number of females who have a PhD. If a third of the male
faculty in the Department have a PhD, then what is the number of female faculty in the
Answer:
8
Step-by-step explanation:
We can start by making the table below to show the given numbers (red) and to assign a variable (x) to the number we want to find: female PhDs.
By subtracting the female numbers from the totals, we can find the corresponding numbers of male PhDs and non-PhDs.
The number of male non-PhDs is twice the number of male PhDs, so we have ...
2(14 -x) = 20 -x
28 -2x = 20 -x . . . . eliminate parentheses
8 = x . . . . . . . . . . . .add 2x-20
The number of female faculty with PhDs is 8.
A recent survey found that 86% of employees plan to devote at least some work time to follow games during the NCAA Men's Basketball Tournament. A random sample of 100 employees was selected. What is the probability that less than 80% of this sample will devote work time to follow games?
Answer:
4.18% probability that less than 80% of this sample will devote work time to follow games
Step-by-step explanation:
Normal probability distribution
When the distribution is normal, we use the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.
Central Limit Theorem
The Central Limit Theorem estabilishes 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.
For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]
In this question, we have that:
[tex]p = 0.86, n = 100[/tex]
So
[tex]\mu = 0.86, s = \sqrt{\frac{0.86*0.14}{100}} = 0.0347[/tex]
What is the probability that less than 80% of this sample will devote work time to follow games?
This is the pvalue of Z when X = 0.8. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{0.8 - 0.86}{0.0347}[/tex]
[tex]Z = -1.73[/tex]
[tex]Z = -1.73[/tex] has a pvalue of 0.0418
4.18% probability that less than 80% of this sample will devote work time to follow games
Can anyone help me with my homework ?
2x+3y=20
7x+2y=53
Answer:
x=7, y=2
Step-by-step explanation:
Solve2x+3y=20for x:
2x+3y=20
2x+3y+−3y=20+−3y
2x=−3y+20
2x/2=-3y+20/2
x= -3/2 y
Let x represent the number. Use the given conditions to write an equation. Solve the equation and find the number.
The product of 8 and a number is 96. Find the number.
Write an equation for the given conditions.
Answer:
12
Step-by-step explanation:
8x=96
x=96/8
x=12
Answer:
12
Step-by-step explanation:
8x=96
96/8
x=12
so the the product of 8and 12=96
2. The width of a rectangle is 12 inches less than its length. The perimeter of the rect-
angle is 56 inches. Find the length and width of the rectangle.
Answer:
[tex] P= 2*Lenght + 2*Width[/tex]
Since the perimeter is 56 inches we can solve for the lenght with this equation:
[tex] 56 in = 2*12in + 2*Length[/tex]
And solving for the length we got:
[tex] Length = \frac{56in -24 in}{2} 16 in[/tex]
So then the lenght = 16 inhes and the width of 12 inches
Step-by-step explanation:
For a rectangle of width 12 inches and lenght y inches we know that the perimeter is given by:
[tex] P= 2*Lenght + 2*Width[/tex]
Since the perimeter is 56 inches we can solve for the lenght with this equation:
[tex] 56 in = 2*12in + 2*Length[/tex]
And solving for the length we got:
[tex] Length = \frac{56in -24 in}{2} 16 in[/tex]
So then the lenght = 16 inhes and the width of 12 inches
MY LAST 2 QUESTION WILL FOREVER BE GRATEFUL PLS HELP WILL GIVE BRANLIEST!! AT LEAST TAKE A LOOK!!!! PLS I AM BEGGING!!!
1. Molly is trying to find a relationship between the largest angle and largest side of a triangle. She has drawn dozens of triangles, and measured their parts. She’s ready to make a conjecture. What kind of reasoning was Molly using? Explain how you know it’s that kind of reasoning.
11. Which step in the proof has a flaw?
Given AB=BC prove B is the midpoint of AC
IMAGE BELOW
A) Step 1
B) Step 3
C) No Flaw.
D) Step 2
Answer:
C.
Step-by-step explanation:
11. There is no flaw since step 1 is given, and there is the right reason for step 2.
1. Molly is using inductive reasoning because she is collecting the data to make a conjecture.
11. There is no flaw.
if r is the radius of a circle and d is its diameter which of the following is an equivalent formula for the circumference c = 2 pie r
a C = pie d2
b C = pie rd
c C = pie d
d C = 2 pie d
Answer:
C
Step-by-step explanation:
C=2pier or pied
Answer:
a. C = 2πr
c. C= πd
both are correct
a circle with circumference 20 has an arc at 72 central angle. what is the length of the arc
Answer:
4 units
Step-by-step explanation:
[tex] \because \: l = \frac{ \theta}{360 \degree} \times c \\ \\ \therefore \: l = \frac{72 \degree}{360 \degree} \times 20 \\ \\ \therefore \: l = \frac{72 \degree}{18\degree} \\ \\ \therefore \: l = 4 \: units[/tex]
Find the slope of the line on the graph.
Write your answer as a fraction or a whole
number, not a mixed number or decimal.
Answer:
1/2
Step-by-step explanation:
Find two points on the line
(2,0) and (4,1)
The slope is given by
m= (y2-y1)/(x2-x1)
=(1-0)/(4-2)
= 1/2
A 12cmx2cm rectangle sits inside a circle with a radius of 8cm. What isnthe area of the shaded region of the circle
Answer:
The answer would 177.06 centimeters
A machine produces 576 units in 18 hours at this rate how many will it produce in 28 hours
Answer: 896
Step-by-step explanation:
Let's use a rule of three here.
[tex]\frac{576}{x}=\frac{18}{28}[/tex]
Solve for x;
[tex]x=\frac{576*28}{18}[/tex]
[tex]x=896[/tex]
The m∠ABC = (10x-5)°and m∠CBD=35°. If the angles are supplementary, find the value of x.
Answer:
15
Step-by-step explanation:
Supplementary angles completes each other to 180°
if the teo angles are supplementary here the the sum of 10x - 5 + 35 should be 180°
10x - 5 + 35 = 180
10x + 30 = 180
10x = 150
x = 15
What is the equation of the line that passes through (5, -2) and (-3, 4)?
Answer:
y = (-3/4)x + 7/4
Step-by-step explanation:
Step 1: Define general form of equation of line
An equation of a straight line on two-dimensional plane could be represented in form of: y = Mx + b, with M is slope and b is y-intercept
Step 2: Set up the system to solve for parameters of equation of line
(solve for M and b)
That equation passes 2 points, which are represented in form of (x, y), (5, -2) and (-3, 4).
Substitute these values of x and y into the original equation in step 1:
-2 = 5M + b
4 = -3M + b
Step 3: Solve the system of equations in step 2 for M and b
Subtract 1st equation from 2nd equation:
6 = -8M
=> M = -6/8 = -3/4
Substitute M back into 1st equation:
=> -2 = 5*(-3/4) + b
=> b = -2 + 15/4
=> b = 7/4
=> The equation of the line that passes through (5, -2) and (-3, 4):
y = (-3/4)x + 7/4
Hope this helps!
:)
Answer:
Y= -4/3(x-7/2)
Step-by-step explanation:
So first calculate the difference between them,
changes by 8 x units, and -6 y units.
Then substitute them into y/x to find gradient
-6/8 = -4/3
so now we have a part of the equation:
Y= -4/3(x-a)
substitute Y= -2 and x=5 (from (5,-2))
-2= -4/3(5-a)
-2= -20/3+4a/3
Multiply by 3 on both sides
-6= -20+4a
add 20 on both sides
14=4a
a=7/2
use this as the value of a
Y= -4/3(x-7/2)
The first digit in any number must be 1, 2, 3, 4, 5, 6, 7, 8, or 9 because we do not write numbers such as 15 as 015. While it is reasonable to think that for most real-life data each digit occurs with equal frequency so that each digit 1, 2, ..., 9 has probability 1/9 of being the first digit, this is not true. It is a surprising phenomenon that in many naturally occurring numbers and web-based data the first digit has a probability distribution known as Benford's law.
Benford's law, also called the first-digit law, states that in lists of numbers from many (but not all) real-life sources of data, the leading digit is distributed in a specific, non-uniform way.
Specifically, for d = 1, 2, 3, 4, 5, 6, 7, 8, 9, Benford's law states P(first digit is d) = log_10(1+(1/d)) . The distribution of the first digit according to Benford's law, calculated to 3 decimal places, is shown in the table below.
Benford's law
First Digit X 1 2 3 4 5 6 7 8 9
Probability .301 .176 .125 .097 .079 .067 .058 .051 .046
Benford's Law and the Equally Likely Model benford equally likely
The law is named after physicist Frank Benford, who stated it in 1938, although it had been previously stated by Simon Newcomb in 1881. A surprising variety of data from the natural sciences, social affairs, and business obeys Benford's law.
This result has been found to apply to a wide variety of data sets, including electricity bills, street addresses, stock prices, population numbers, death rates, lengths of rivers, physical and mathematical constants, and processes described by power laws (which are very common in nature).
Numbers that are assigned, such as social security numbers and zip codes, or data with a fixed maximum, such as deductible contributions to individual retirement accounts, or randomly generated numbers, do not follow Benford's law.
The figure below shows how the distribution of the first digit of various naturally occurring and web-based data compares with Benford's law.
benford natural data web data
Figure information. Earthquakes: depth in km of 248,915 quakes, 1989-2009; source National Earthquake Information Center, United States Geological Survey. Minnesota lakes: size in acres of approx. 1100 lakes; source Wikipedia. Births: number of births in each county of the United States (approximately 3200), 2010; source: US Census Bureau. Diggs: total number of diggs for each of the top 1000 diggers at digg.com; source: socialblade.com.
Question 1:
(1a). What is the expected value of the first digit when the first digit follows Benford's law?
expected value (Use 3 decimal places).
(1b). What is the expected value of the first digit when the possible first digits are equally likely?
expected value (Use 3 decimal places).
(1c). What is the standard deviation of the first digit when the first digit follows Benford's Law?
Answer:
0.699
Step-by-step explanation:
got it on khan academy, should get brainliest thanks
Solve the system of equations by using substitution
Y=2x+3
Y=x+2
Since our first equation reads y = 2x + 3, we can substitute a 2x + 3
in for y in our second equation and then solve from there.
So we have 2x + 3 = x + 2.
Now subtract x from both sides to get x + 3 = 2.
Now subtract 3 from both sides to get x = -1.
To find y, plug -1 back into either equation.
I have chosen to plug it into the second.
So we have y = (-1) + 2 which simplifies to 1.
So our solution to this system is (-1, 1).
Compute 8P2 *
16
O 56
O 28
O
none of these are correct
0.2x + (-0.9) + 1.7 = 9.6
0.2x + 0.8 = 9.6
X=
WHAT DOES x =
Answer:
x =44
Step-by-step explanation:
0.2x + (-0.9) + 1.7 = 9.6
Combine like terms
.2x +.8 = 9.6
Subtract .8 from each side
.2x +.8 -.8 = 9.6 -.8
.2x = 8.8
Divide each side by .2
.2x/.2 = 8.8/.2
x =44
Simplify
20x over 70x
Answer:
The answer is 2/7.
Step-by-step explanation:
You have to cut out the common terms :
[tex] \frac{20x}{70x} [/tex]
[tex] \frac{20}{70} [/tex]
[tex] \frac{2}{7} [/tex]
no guess please explain
In the circle above, P is the center,What is the value, in degrees, of θ?
Answer:
45°
Step-by-step explanation:
There is a propiety that says "The measure of the inscribed angle is half that of the arc that the two sides cut out of the circle."
So the central angle is 90, the inscribed angle will be 90/2=45°
Which of the following is the slope of the line that passes through the points (-3,5) and (-3,-2)
Answer:
undefined.
Step-by-step explanation:
-2-5/-3-(-3)
-7/0
Undefined
B
ABC is a right-angled triangle.
AC = 16 cm
Angle C = 90°
А.
size of angle B : size of angle A = 3:2
С
16 cm
Work out the length of AB.
Give your answer correct to 3 significant figures.
Answer:
19.8 cm
Step-by-step explanation:
Angle B is the complement of angle A, so we have this relation for the angles:
B/A = 3/2 = (90°-A)/A
2(90° -A) = 3A . . . . . cross multiply
180° = 5A . . . . . . . . . eliminate parentheses, add 2A
36° = A . . . . . . . . . . . divide by 5
The relations expressed by the mnemonic SOH CAH TOA remind you that ...
Cos = Adjacent/Hypotenuse
cos(A) = AC/AB
AB = AC/cos(A) = (16 cm)/cos(36°)
AB ≈ 19.8 cm
2/5 of the members of a school band are 6th graders. What percent of
the students in the band are non-sixth graders?
Answer:
60%
Step-by-step explanation:
3/5 is 60%
Answer:
60%
Step-by-step explanation:
5/5 minus 2/5 is 3/5
5 divided by 3 is .6
in order to find out the percent move the decimal over to the right
When Ryan was born, he weighed 7 pounds.At 6 months, he weighed 11.2 pounds. Amanda weighed 6 pounds when she was born, and 12.9 pounds at 6 months. Which baby had a greater percent increase in weight? Explain
Answer:
✅Amanda had a greater percent increase in weight.
Step-by-step explanation:
The percent change in Ryan’s weight was 42/7 or 60%. The percent change in Amanda’s weight was 6.9/6, or 115%. Amanda had a greater percent increase in weight.
IamSugarBee
Answer:
The percent change in Ryan’s weight was 4.2/7, or 60%. The percent change in Amanda’s weight was 6.9/6 , or 115%. Amanda had a greater percent increase in weight.
Step-by-step explanation:
its the sample answer i just did it
Gordon Miller's job shop has four work areas, A, B, C, and D. Distances in feet between centers of the work areas are: A B C D A − 5 9 7 B − − 6 8 C − − − 11 D − − − − Workpieces moved per week between work areas are: A B C D A − 900 900 500 B − − 500 200 C − − − 600 D − − − − It costs Gordon $22 to move 1 work piece 1 foot.What is the weekly total material handling cost of the layout?
Answer: $600,600
Step-by-step explanation:
Total handling cost :
Workpiece moved * cost * distance
Work area A :
-, (5 × 22 × 900), (9 × 22 × 900), (7 × 22 × 500)
-, 99000, 178200, 77000
Work area B:
-, -, (6 × 22 × 500), (8 × 22 × 200)
-, -, 66000, 35200
Work area C:
-, -, -, (11 × 22 × 600)
-,-,-, 145200
Work area D:
-, -, -, -
Total weekly handling cost :
(99000 + 178200 + 77000 + 66000 + 35200 + 145200)
= $600,600
Kindly check attached picture for more explanation
If \\(z_1=3+2i\\) and \\(z_2=4+3i\\) and are complex numbers, find \\(z_1z_2\\)
[tex]z_1z_2=(3+2i)(4+3i)=3\cdot4+2i\cdot4+3\cdot3i+2i\cdot3i[/tex]
[tex]z_1z_2=12+8i+9i+6i^2[/tex]
[tex]i^2=-1[/tex], so
[tex]z_1z_2=12+8i+9i-6=\boxed{6+17i}[/tex]
New York State's "Quick Draw" lottery moves right along. Players choose between one and 10 numbers from the range one to 80; 20 winning numbers are displayed on a screen every four minutes. If you choose just one number, your probability of winning is 20/80, or 0.25. Lester plays one number fourteen times as he sits in a bar. What is the probability that all fourteen bets lose
Answer:
0.0178
Step-by-step explanation:
For computation of probability that all fourteen bets lose first we need to find out the Probability of losing in 1 bet is shown below:-
Probability of losing in 1 bet = 1 - P(winning)
= 1 - 0.25
= 0.75
With the help of probability of losing in 1 bet we can find out the Probability of losing in 8 bets which is here below:-
= Probability of losing in 1 bet ^ Number of loosing bets
= 0.75 ^ 14
= 0.017817948
or
= 0.0178
Therefore for computing the probability that all fourteen bets lose we simply applied the above formula.