Please help me with solving these. I’d really appreciate your help. Thank you very much.
Answers
Answer:
Problem 17)
[tex]\displaystyle y=-\frac{5}{2}x+\frac{7}{2}[/tex]
Problem 18)
[tex]\displaystyle y=\frac{3}{2}x-\frac{3}{2}+\frac{\pi}{4}[/tex]
Step-by-step explanation:
Problem 17)
We have the curve represented by the equation:
[tex]\displaystyle 4x^2+2xy+y^2=7[/tex]
And we want to find the equation of the tangent line to the point (1, 1).
First, let's find the derivative dy/dx. Take the derivative of both sides with respect to x:
[tex]\displaystyle \frac{d}{dx}\left[4x^2+2xy+y^2\right]=\frac{d}{dx}[7][/tex]
Simplify. Recall that the derivative of a constant is zero.
[tex]\displaystyle \frac{d}{dx}[4x^2]+\frac{d}{dx}[2xy]+\frac{d}{dx}[y^2]=0[/tex]
Differentiate. We can differentiate the first term normally. The second term will require the product rule. Hence:
[tex]\displaystyle 8x+\left(2y+2x\frac{dy}{dx}\right)+2y\frac{dy}{dx}=0[/tex]
Rewrite:
[tex]\displaystyle \frac{dy}{dx}\left(2x+2y\right)=-8x-2y[/tex]
Therefore:
[tex]\displaystyle \frac{dy}{dx}=\frac{-8x-2y}{2x+2y}=-\frac{4x+y}{x+y}[/tex]
So, the slope of the tangent line at the point (1, 1) is:
[tex]\displaystyle \frac{dy}{dx}\Big|_{(1, 1)}=-\frac{4(1)+(1)}{(1)+(1)}=-\frac{5}{2}[/tex]
And since we know that it passes through the point (1, 1), by the point-slope form:
[tex]\displaystyle y-1=-\frac{5}{2}(x-1)[/tex]
If desired, we can simplify this into slope-intercept form. Therefore, our equation is:
[tex]\displaystyle y=-\frac{5}{2}x+\frac{7}{2}[/tex]
Problem 18)
We have the equation:
[tex]\displaystyle y=\tan^{-1}\left(x^3\right)[/tex]
And we want to find the equation of the tangent line to the graph at the point (1, π/4).
Take the derivative of both sides with respect to x:
[tex]\displaystyle \frac{dy}{dx}=\frac{d}{dx}\left[\tan^{-1}(x^3)][/tex]
We can use the chain rule:
[tex]\displaystyle \frac{d}{dx}[u(v(x))]=u'(v(x))\cdot v(x)[/tex]
Let u(x) = tan⁻¹(x) and let v(x) = x³. Thus:
(Recall that d/dx [arctan(x)] = 1 / (1 + x²).)
[tex]\displaystyle \frac{d}{dx}\left[\tan^{-1}(x^3)\right]=\frac{1}{1+v^2(x)}\cdot 3x^2[/tex]
Substitute and simplify. Hence:
[tex]\displaystyle \frac{d}{dx}\left[\tan^{-1}(x^3)\right]=\frac{1}{1+v^2(x)}\cdot 3x^2=\frac{3x^2}{1+x^6}[/tex]
Then the slope of the tangent line at the point (1, π/4) is:
[tex]\displaystyle \frac{dy}{dx}\Big|_{x=1}=\frac{3(1)^2}{1+(1)^6}=\frac{3}{2}[/tex]
Then by the point-slope form:
[tex]\displaystyle y-\frac{\pi}{4}=\frac{3}{2}(x-1)[/tex]
Or in slope-intercept form:
[tex]\displaystyle y=\frac{3}{2}x-\frac{3}{2}+\frac{\pi}{4}[/tex]
Related Questions
Help plz I just need the awnser to this question
Answers
Answer:
A seems to be correct
Step-by-step explanation:
Ellen, Nick, and Ryan went shopping together. One of them bought a hat, another bought sunglasses, and another bought a belt. One paid $6, another paid $8, and another paid $10.
1) Nick bought the hat.
2) Ellen spent $8.
3) The belt did not cost $10.
4) Ryan spent the most. Which of the following is true?
(a) Nick bought the hat for $10.
(b) Ellen bought the belt for $8.
(c) Ryan bought the sunglasses for $8.
(d) Ryan bought the belt for $10
(e) Ryan bought the hat for 56.
Answers
Answer:
see down
Step-by-step explanation:
d is correct answer
Roulette is a casino game that involves spinning a ball on a wheel that is marked with numbered squares that are red, black, or green. Half of the numbers 1 - 36 are colored red and half are black and the numbers 0 and 00 are green. Each number occurs only once on the wheel. What is the probability of landing on an even number and a number greater than 17? (A number is even if it is divisible by 2. 0 and 00 are considered even as well.)
Answers
Answer:
the wording (punctuation) of the question can lead to different interpretations....
I assume that the question was >17 & even which is "5/19",
BUT... it can also be read as two questions
first >17 which is "10/19"
and second an even number which is "9/19"
BUT !!! I think that the question answer is 5/19
Step-by-step explanation:
Even Number = 18/38 = 9/19
greater 17 = 20/38 = 10/19
Even & greater 17 = 10/38 = 5/19
Solve the simultaneous equations
6
x
+
2
y
=
12
5
x
+
2
y
=
8
Answers
Answer: x=4, y=-6
Step-by-step explanation:
what is the answer to 10% of 900
Answers
Answer:
90 cause 90 times 10 is 900 and 10% times 10 is 100%
Step-by-step explanation:
Answer: 90
Step-by-step explanation: 900 × .10 = 90
Find the slope of the line y= -3x+7
Answers
Answer:
If you had a line of x = 7, (or any time you have an equation where x equals a number) then you would have a vertical line. In every vertical line, the slope is undefined. In equations of lines that are in the format of y = mx + b, the slope is represented by the "m".Answer:
-3
Explanation:
The given equation is in slope-intercept form. The format of slope-intercept is y = mx + b, where m is the slope and b is the y-intercept.
The slope is the coefficient of x.
In the equation y = -3x + 7, the slope is -3, because -3 is the coefficient of x.
Hence, the slope is -3.A telephone exchange operator assumes that 7% of the phone calls are wrong numbers. If the operator is accurate, what is the probability that the proportion of wrong numbers in a sample of 459 phone calls would differ from the population proportion by more than 3%
Answers
Answer:
0.0118 = 1.18% probability that the proportion of wrong numbers in a sample of 459 phone calls would differ from the population proportion by more than 3%
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
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.
Central Limit Theorem
The Central Limit Theorem establishes 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]
A telephone exchange operator assumes that 7% of the phone calls are wrong numbers.
This means that [tex]p = 0.07[/tex]
Sample of 459 phone calls:
This means that [tex]n = 459[/tex]
Mean and standard deviation:
[tex]\mu = p = 0.07[/tex]
[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\sqrt{\frac{0.07*0.93}{459}}} = 0.0119[/tex]
What is the probability that the proportion of wrong numbers in a sample of 459 phone calls would differ from the population proportion by more than 3%?
Proportion below 0.07 - 0.03 = 0.04 or above 0.07 + 0.03 = 0.1. Since the normal distribution is symmetric, these probabilities are the same, which means that we find one of them and multiply by 2.
Probability the proportion is below 0.04.
p-value of Z when X = 0.04. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{0.04 - 0.07}{0.0119}[/tex]
[tex]Z = -2.52[/tex]
[tex]Z = -2.52[/tex] has a p-value of 0.0059
2*0.0059 = 0.0118
0.0118 = 1.18% probability that the proportion of wrong numbers in a sample of 459 phone calls would differ from the population proportion by more than 3%
The polynomial 3x² + mx? - nx - 10 has a factor of (x - 1). When divided by x + 2, the remainder is 36. What are
the values of m and n?
Answers
Answer:
[tex]m = 12[/tex]
[tex]n =3[/tex]
Step-by-step explanation:
Given
[tex]P(x) = x^3 + mx^2 - nx - 10[/tex]
Required
The values of m and n
For x - 1;
we have:
[tex]x - 1 = 0[/tex]
[tex]x=1[/tex]
So:
[tex]P(1) = (1)^3 + m*(1)^2 - n*(1) - 10[/tex]
[tex]P(1) = 1 + m*1 - n*1 - 10[/tex]
[tex]P(1) = 1 + m - n - 10[/tex]
Collect like terms
[tex]P(1) = m - n + 1 - 10[/tex]
[tex]P(1) = m - n -9[/tex]
Because x - 1 divides the polynomial, then P(1) = 0;
So, we have:
[tex]m - n -9 = 0[/tex]
Add 9 to both sides
[tex]m - n = 9[/tex] --- (1)
For x + 2;
we have:
[tex]x + 2 = 0[/tex]
[tex]x = -2[/tex]
So:
[tex]P(-2) = (-2)^3 + m*(-2)^2 - n*(-2) - 10[/tex]
[tex]P(-2) = -8 + 4m + 2n - 10[/tex]
Collect like terms
[tex]P(-2) = 4m + 2n - 10 - 8[/tex]
[tex]P(-2) = 4m + 2n - 18[/tex]
x + 2 leaves a remainder of 36, means that P(-2) = 36;
So, we have:
[tex]4m + 2n - 18 = 36[/tex]
Collect like terms
[tex]4m + 2n = 36+18[/tex]
[tex]4m + 2n = 54[/tex]
Divide through by 2
[tex]2m + n=27[/tex] --- (2)
Add (1) and (2)
[tex]m + 2m - n + n = 9 +27[/tex]
[tex]3m =36[/tex]
Divide by 3
[tex]m = 12[/tex]
Substitute [tex]m = 12[/tex] in (1)
[tex]m - n =9[/tex]
Make n the subject
[tex]n = m - 9[/tex]
[tex]n = 12 - 9[/tex]
[tex]n =3[/tex]
Tim Hortons is hiring and offers $200 every week plus $5 per hour. McDonalds offers $300 every week plus $2 per hour. State the conditions under which Tim Hortons is the better employer
Answers
Answer:
Assuming you want better payment each week, any number of hours above 33.333 or 33 hours and 20 minutes per week
Step-by-step explanation:
There are several ways we could do this. We could say we want to have Tim Hortons be the better employer on the first week, or after so many weeks by adjusting the hours. I am going to assume we are saying we want it to be a better employer on the first week, so the profit will be the amount made every week plus the money made per hour times the number of hours.
Let's say number of hours is H
So Tim Hortons winds up as 200 + 5H for one week and Mcdonalds will be 300 + 2H.
If you set the two expressions equal to each other you will find where they intersect, which means at that number of hours they will give the same amount of money while any amount before one of the companies will give more and after that many hours the other will. Let's go ahead and solve.
200 + 5H = 300 + 2H
3H = 100
H = 100/3
So H is about 33.333. let's check.
200 + 5(33.333) = 366.665 which rounds to 366.67 dollars
300 + 2(33.333) = 366.666 which also rounds to 366.67 dollars
So at 33.333 hours both give 366.67 dollars. Let's look at a value below it, say 32.
200 + 5(32) = 360
300 + 2(32) = 364
So you can see here Tim Hortons pays less. Now we will try 34 as a value above 33.333
200 + 5(32) = 370
300 + 2(32) = 368
Here Mcdonalds pays less. This was to show that values below 33.333 make Tim Hortonspay less and values above 33.333 make Mcdonalds pay less. In other words any value above 33.333 hours will have Tim Hortons be the better employer. And this is per week
I want to repeat, you can expand this to be multiple weeks and see which of the two becomes better in that epriod of time. This was, I think, the simplest way to answer though.
So the conditions where Tim Horton pays more isif you work more than 33.333 hours per week. This will make them pay more every single week.
Adult men have heights with a mean of 69.0 inches and a standard deviation of 2.8 inches. Find the z-score of a man 71.2 inches tall. (to 2 decimal places)
Answers
Answer:
0.7857
Step-by-step explanation:
Given :
Mean = 69 inches
Standard deviation, = 2.8 inches
The Zscore of a man who is 71.2 inches
The ZSCORE is obtained using the relation :
Zscore = (Score, x - mean) / standard deviation
Zscore = (71.2 - 69) / 2.8
Zscore = 2.2 / 2.8
Zscore = 0.7857
What is the length of an arc with a central angle of 2/3pi radians and a radius of 24 centimeters?
Use 3.14 for pi.
Enter your answer, as a decimal, in the box.
Answers
9514 1404 393
Answer:
50.24 cm
Step-by-step explanation:
Fill in the given numbers and do the arithmetic.
s = rθ
s = (24 cm)(2/3π) = (24 cm)(2/3)(3.14) = 50.24 cm
Please help it’s kinda confusing only got 20 minutes left !!
Answers
I’m struggling with this question someone help ASAP plz
Answers
Answer:
The correct answer is:
30 = 10 + 3(h - 2)30 = 10 + 3h - 6
26 = 3h
h = 8.67
Step-by-step explanation:
We're gonna calculate by our part the hours a new costumer can rent a bike and pay a total of $30, using the original function:
f (h) = 10 + 3(h - 2)Where:
f (h) = Total cost. h = the number of hours.We know The total money spent must be $30, by this reason, the function change to:
30 = 10 + 3(h - 2)Now, we must clear the h variable, by this reason, we multiply 3 by h and 2:
30 = 10 + 3*h - 3*2 30 = 10 + 3h - 6We pass the 10 and the -6 to the left side of the equality:
30 - 10 + 6 = 3h (Remember to change the signs when you do this step) 26 = 3hFinally, we pass the 3 to the left side of the equality:
26 / 3 = h (the 3 pass to divide because is multiplying the x)
8.666666666667 = hIf we just use two decimals, the number of hours is:
h = 8.67How the third option is the one that shows this calculation and result, that is the correct answer.
Which System of inequalities has this graph as its solution?
A. y<2x-3
y<1/3x+4
B. y>2x-3
y>1/3x+4
C. y>2x-3
y<1/3x+4
D. y<2x-3
y>1/3x+4
Answers
Answer: B
Step-by-step explanation:
The line [tex]y=2x+3[/tex] is dotted and shaded above.
Eliminate A and D.Similarly, the line [tex]y=\frac{1}{3}x+4[/tex] is also shaded above.
Eliminate C.This leaves B as the correct answer.
Find a power series representation for the function. (Assume a>0. Give your power series representation centered at x=0 .)
f(x)=x2a7−x7
Answers
Answer:
Step-by-step explanation:
Given that:
[tex]f_x = \dfrac{x^2}{a^7-x^7}[/tex]
[tex]= \dfrac{x^2}{a^7(1-\dfrac{x^7}{a^7})}[/tex]
[tex]= \dfrac{x^2}{a^7}\Big(1-\dfrac{x^7}{a^7} \Big)^{-1}[/tex]
since [tex]\Big((1-x)^{-1}= 1+x+x^2+x^3+...=\sum \limits ^{\infty}_{n=0}x^n\Big)[/tex]
Then, it implies that:
[tex]\implies \dfrac{x^2}{a^7} \sum \limits ^{\infty}_{n=0} \Big(\Big(\dfrac{x}{a} \Big)^{^7} \Big)^n[/tex]
[tex]= \dfrac{x^2}{a^7} \sum \limits ^{\infty}_{n=0} \Big(\dfrac{x}{a} \Big)^{^{7n}}[/tex]
[tex]= \dfrac{x^2}{a^7} \sum \limits ^{\infty}_{n=0} \Big(\dfrac{x^{7n}}{a^{7n}} \Big)}[/tex]
[tex]\mathbf{= \sum \limits ^{\infty}_{n=0} \dfrac{x^{7n+2}}{a^{7n+7}} }}[/tex]
Find the measure of of RA.
Answers
Answer:
RA = 24
Step-by-step explanation:
Since the triangle is isosceles ( 2 equal sides ) , then LU is a perpendicular bisector , so
AU = RU , that is
4r = 18 - 2r ( add 2r to both sides )
6r = 18 ( divide both sides by 6 )
r = 3
Then
RA = 18 - 2r + 4r = 18 + 2r = 18 + 2(3) = 18 + 6 = 24
HW HELP ASAP PLZZZZZ
Answers
Answer:
p = 15/x
x= -3
Step-by-step explanation:
For the first problem, we can expand the equation to 4px+4=64
then simplify it to:
4px=60
then divide 4x from both sides of the equation
p=60/4x
then simplify:
p=15/x
For the second problem:
plug in -5 for p so the equation would look like
4(-5x +1)=64
simplify
-20x=60
x= -3
Sam thinks of a 4 digit number. The digit in the one’s place is 3 less than the digit in the ten’s place and digit in thousand’s place is 5 less than the digit in hundred’s place. The value of the hundred’s place is 800. The digit in ten’s place is the greatest even number. What is the number Sam is thinking of?
Answers
9514 1404 393
Answer:
3885
Step-by-step explanation:
The hundreds digit is 8, and the thousands digit is 5 less, so is 3.
The tens digit is 8 (the largest even digit), and the ones digit is 3 less, so is 5.
The number is ...
3885
A mechanic charges $65 for an engine check and $20 per hour for his
services. Which of the following is a linear model of his charges.
y=20x+65
y=65x+20
y=3.25x+65
O y=3.25x+20
Question 5
Answers
Answer:
y = 65 + 20x
Step-by-step explanation:
Okay, when you're talking about linear equations try to find the fixed value, and then the changing one.
The fixed value will be by itself
The value that varies will have a variable next to it (x, y, z, whatever)
Then, the answer has to be
y = 65 + 20x
a. 23 = -11 - 4x
b. 23 = -11 + (-4x)
C. 23 + 11 = -11 + (-4x) + 11
d. 23 + 11 = -11 + 11 +(-4x)
e. 34 = - 4x
f. 34/-4 = -4x/ -4
g. -8.5 = x
Which properties of equality justify steps c and f?
A.) addition property of equality; subtraction property of equality B.) addition property of equality; division property of equality C.) subtraction property of equality; multiplication property of equality D.) multiplication property of equality; division property of equality
Answers
Answer:
B.) addition property of equality; division property of equality
Plss helpp
I need to pass
Answers
9514 1404 393
Answer:
P' = (3, -5)
Step-by-step explanation:
Rotation 180° about the origin is the same as reflection across the origin. The transformation is given by ...
(x, y) ⇒ (-x, -y) . . . . . . the signs of the coordinates are both changed
P(-3, 5) ⇒ P'(3, -5)
In ABC, if CB AC≅ , m∠A = 3x + 18, m∠B = 7x – 58, and m∠C = 2x – 8, find x and the measure of each angle.
Answers
9514 1404 393
Answer:
x = 19
A = 30°
B = C = 75°
Step-by-step explanation:
In an isosceles triangle, the angles opposite the congruent sides have the same measures.
A = B
3x +18 = 7x -58
76 = 4x . . . . . . . . add 58-4x
19 = x . . . . . . . . . divide by 4
Then the equal angles measure ...
A = B = 3(19) +18 = 75
C = 2(19) -8 = 30
Angles A, B, C measure 75°, 75°, 30°, respectively.
_____
Alternate solution
The sum of angles in a triangle is 180°, so you could write ...
(3x +18) +(7x -58) +(2x -8) = 180
12x = 228 . . . . . add 48
x = 19 . . . . . divide by 12
9 friends are lining up. Joe, Susan, John, and Meredith must be beside each other. How many ways can they line up?
Answers
This is one single number slightly over 17 thousand.
You may need to erase the comma when typing the answer in.
=========================================================
Explanation:
Let's say that another person steps in for Joe, Susan, John, and Meredith. I'll refer to this person as the teacher (perhaps these 9 friends are students on a field trip).
The 9 friends drops to 9-4 = 5 people when those four named people leave the group temporarily. Then it bumps up to 5+1 = 6 people when the teacher steps in. Wherever the teacher is located, the four friends that left will replace the teacher. This guarantees that those four friends stick together.
There are 6! = 6*5*4*3*2*1 = 720 ways to arrange those 6 people. The exclamation mark is a factorial symbol.
Within any of those 720 permutations, we have 4! = 4*3*2*1 = 24 ways to arrange those group of named people when they come back to replace the teacher.
So overall the answer is 4!*6! = 24*720 = 17,280
You may need to erase the comma when typing the answer in.
-------------
Side note: There are 9! = 362,880 ways to arrange all nine friends regardless if those four mentioned people stick together or not. We see that they stick together roughly (17,280)/(362,880) = 0.0476 = 4.76% of the time.
A margin of error tells us how often the confidence interval estimates the parameter incorrectly. how often a confidence interval is correct. how accurate the statistic is when using it to estimate the parameter.
Answers
Answer:
how accurate the statistic is when using it to estimate the parameter.
Step-by-step explanation:
The margin of error may be referred to as a range or interval around a calculated statistic. The margin of error usually employed when calculating the confidence interval, will give a certain range of value within the sample statistic. This is sample statistic and margin is used to estimate the parameter albeit a certain percentage or proportion within the sample statistic. This provides the accuracy level at which the statistic will estimate the parameter.
Margin of Error :
Margin of Error = Zcritical * σ/√n ; OR
Margin of Error = Tcritical * s/√n
Where ;
σ = population standard deviation
s = sample standard deviation
Type the correct answer in each box. Use numerals instead of words. If necessary, use / for the fraction bar(s). Consider the equation below. The value of x in terms of b is . The value of x when b is 3 is .
Answers
Answer: x=-3/3=-1
Step-by-step explanation:
To solve for x in terms of b, simply treat b as a number, and solve for x as usual: first of all, we expand the left hand side:
-2bx+10=16
Subtract 10 from both sides:
-2bx=6
Divide both sides by -2b:
x=6/-2b=-3/b
This means that in particular, if we set b=3 , we have
x=-3/3=-1
The following data were obtained from 4 people Pre-Test Value Post-test Value 43 42 28 29 31 30 28 25 You may also assume that the sample standard deviation for the four differences is 1.6. What is the correct t-statistic and the degrees of freedom for these data
Answers
Answer:
Test statistic = 1.25
Degree of freedom = 3
Step-by-step explanation:
The following data were obtained from 4 people
Pre-Test Value Post-test Value __ d
43 ________42 _________ 1
28_______ 29 ________ - 1
31 ________30 _________ 1
28 ________ 25 _________ 3
μd = (1 + - 1 + 1 + 3) / 4 = 4 /4 = 1
The mean difference, μd = 1
The standard deviation of difference, Sd = 1.6
The test statistic = μd / (Sd / √n)
Test statistic = 1 / (1.6/2) = 1 / 0.8
Test statistic = 1.25
Degree of freedom, = n - 1 = 4 - 1 = 3
Which of these figures has rotational symmetry?
Answers
Hello!
The answer is a.
Good luck! :)
A sample of 24 observations is taken from a population that has 150 elements. The sampling distribution of is _____. an. approximately normal because is always approximately normally distributed b. approximately normal because the sample size is large in comparison to the population size c. approximately normal because of the central limit theorem d. normal if the population is normally distributed
Answers
Answer:
d. normal if the population is normally distributed
Step-by-step explanation:
Central Limit Theorem
The Central Limit Theorem establishes 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.
In this question:
Sample size less than 30, so only will be normal if the population is normally distribution, and thus the correct answer is given by option d.
A researcher believes that 9% of males smoke cigarettes. If the researcher is correct, what is the probability that the proportion of smokers in a sample of 664 males would differ from the population proportion by greater than 3%
Answers
Answer:
0.0070 = 0.70% probability that the proportion of smokers in a sample of 664 males would differ from the population proportion by greater than 3%
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
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.
Central Limit Theorem
The Central Limit Theorem establishes 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]
A researcher believes that 9% of males smoke cigarettes.
This means that [tex]p = 0.09[/tex]
Sample of 664
This means that [tex]n = 664[/tex]
Mean and standard deviation:
[tex]\mu = p = 0.09[/tex]
[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.09*0.91}{664}} = 0.011[/tex]
What is the probability that the proportion of smokers in a sample of 664 males would differ from the population proportion by greater than 3%?
Proportion below 9 - 3 = 6% or above 9 + 3 = 12%. Since the normal distribution is symmetric, these probabilities are equal, so we find one of them and multiply by 2.
Probability the proportion is below 6%
P-value of Z when X = 0.06. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{0.06 - 0.09}{0.011}[/tex]
[tex]Z = -2.7[/tex]
[tex]Z = -2.7[/tex] has a p-value of 0.0035
2*0.0035 = 0.0070
0.0070 = 0.70% probability that the proportion of smokers in a sample of 664 males would differ from the population proportion by greater than 3%
Camille bought a set of kitchen chairs discounted 25% off of the original price of $170. What was the dollar amount of discount of the set of chairs?
Answers
Answer:
$42.50
Step-by-step explanation:
All you have to do is simply multiply
170 x 0.25=$42.50
