HELP PLEASE. Will give maximum points (100). I’m desperate. Will give brainiest for the correct answer, if wrong answer is given on purpose, I will report. Plz help.
Answer:
C, D, D.
Step-by-step explanation:
Problem 6)
We want to determine the equation of the graphed inequality.
First, let's determine the equation of the line for the inequality. We can see that it passes through the points (-2, 0) and (0, 2). Find the slope:
[tex]\displaystyle m=\frac{\Delta y}{\Delta x}=\frac{2-0}{0-(-2)}=\frac{2}{2}=1[/tex]
So, the slope of the line is one.
And since it passes through the point (0, 2), our y-intercept is two. Therefore, the equation of the line is:
[tex]y=x+2[/tex]
Next, notice that the shaded region is below the line. Also, the line itself is also shaded.
Since the shaded region is below the line, y is less than the graph of the line and since the line itself is shaded, our sign is less than or equal to.
Hence:
[tex]y \leq x + 2[/tex]
Our answer is C.
Problem 7)
We have the inequality:
[tex]-2x+8+5x>2x+1[/tex]
First, solve the inequality. Combine like terms:
[tex]3x+8>2x+1[/tex]
Subtract x from both sides:
[tex]x+8>1[/tex]
And subtract 8 from both sides:
[tex]x>-7[/tex]
Therefore, any value greater than -7 will satisfy the inequality.
Out of the choices, the only choice greater than -7 is -5.
So, our answer is D.
Problem 8)
We have the inequality:
[tex]5x+7\leq 8x-3+2x[/tex]
Again, solve the inequality. Combine like terms:
[tex]5x+7\leq 10x-3[/tex]
Subtract 5x from both sides:
[tex]7\leq 5x-3[/tex]
And add three to both sides:
[tex]10\leq 5x[/tex]
Divide both sides by five:
[tex]2\leq x[/tex]
Flip:
[tex]x\geq 2[/tex]
Therfore, any value greater than or equal to 2 will satisfy the inequality.
Out of the choices, the only choice greater than or equal to 2 is 2.
So, our answer is D.
A tax form asks people to identify their age, annual income, number of dependents, and social security number. For each of these four variables, identify the scale of measurement that probably is used and identify whether the variable is continuous or discrete.
Variable Nominal Ordinal Interval Ratio
Social security number
Annual income
Number of dependents
Variable Discrete Continuous
Social security number
Annual income
Number of dependents
Answer:
Types of variables:
Continuous variable include: income
Discrete variable include: number of dependents
Scale of measurement:
Nominal data include: Social security number
There is no ordinal data included
There is no interval data included
Ratio data include: Annual income,
Number of dependents.
Explanation:
Continuous variables are variables that are obtained by just counting, example: counting the number of times someone eats in a day.
Discrete variables are simply variables that are measured and are usually more precise than continuous variables, example: time, weight, length etc.
Nominal data are data types that are in the form of labels or names and do not have any particular order, example :social security number basically identifies a person and is not ranked or ordered in any way.
Ordinal data are data types that also in the form of names but with ranking and order.
Interval data are data types that rank and order data but with continuous measurement that may take on negative values, example measure of temperature.
Ratio data is same as interval data but does not take negative values, example we can not say that someone is -6 years old.
A student takes an exam containing 16 true or false questions. If the student guesses, what is the probability that he will get exactly 14 questions right
Answer:
0.001831055
Step-by-step explanation:
Here, n = 16, p = 0.5, (1 - p) = 0.5 and x = 14
As per binomial distribution formula P(X = x) = nCx * p^x * (1 - p)^(n - x)
We need to calculate P(X = 14)
P(x =14) = 16C14 * 0.5^14 *(1-0.5)^2
= 120 * 0.5^14 *(1-0.5)^2
= 0.001831055
what is the cost to drive from san francisco to los angeles (405 mi) if the cost of gasoline is $2.34/gal and the automobile gets 8.5 mi/L
Answer:
The cost is $ 29.5.
Step-by-step explanation:
distance = 405 miles
Cost = $ 2.34 /gal
Average = 8.5 miles per litre
So, the amount of gasoline to travel for 405miles
= 405/8.5 = 47.65 liter
1 gal = 3.785 liters
So,
47.65 liter = 47.65 / 3.785 = 12.6 gal
So, the cots is
= $ 2.34 x 12.6 = $29.5
a bag contain 3 black balls and 2 white balls.
1. A ball is taken from the black and then replaced, a second is taken. what is the probabilities that.
(a) there are both black,
(b)one is black one is white,
(c) at lease one is black,
(d) at most one is one is black.
2. find out if all the balls are chosen without replacement.
please kindly solve with explanation. thank you.
Answer:
Step-by-step explanation:
Total number of balls = 3 + 2 = 5
1)
a)
[tex]Probability \ of \ taking \ 2 \ black \ ball \ with \ replacement\\\\ = \frac{3C_1}{5C_1} \times \frac{3C_1}{5C_1} =\frac{3}{5} \times \frac{3}{5} = \frac{9}{25}\\\\[/tex]
b)
[tex]Probability \ of \ one \ black \ and \ one\ white \ with \ replacement \\\\= \frac{3C_1}{5C_1} \times \frac{2C_1}{5C_1} = \frac{3}{5} \times \frac{2}{5} = \frac{6}{25}[/tex]
c)
Probability of at least one black( means BB or BW or WB)
[tex]=\frac{3}{5} \times \frac{3}{5} + \frac{3}{5} \times \frac{2}{5} + \frac{2}{5} \times \frac{3}{5} \\\\= \frac{9}{25} + \frac{6}{25} + \frac{6}{25}\\\\= \frac{21}{25}[/tex]
d)
Probability of at most one black ( means WW or WB or BW)
[tex]=\frac{2}{5} \times \frac{2}{5} + \frac{3}{5} \times \frac{2}{5} \times \frac{2}{5} + \frac{3}{5}\\\\= \frac{4}{25} + \frac{6}{25} + \frac{6}{25}\\\\=\frac{16}{25}[/tex]
2)
a) Probability both black without replacement
[tex]=\frac{3}{5} \times \frac{2}{4}\\\\=\frac{6}{20}\\\\=\frac{3}{10}[/tex]
b) Probability of one black and one white
[tex]=\frac{3}{5} \times \frac{2}{4}\\\\=\frac{6}{20}\\\\=\frac{3}{10}[/tex]
c) Probability of at least one black ( BB or BW or WB)
[tex]=\frac{3}{5} \times \frac{2}{4} + \frac{3}{5} \times \frac{2}{4} + \frac{2}{5} \times \frac{3}{4}\\\\=\frac{6}{20} + \frac{6}{20} + \frac{6}{20} \\\\=\frac{18}{20} \\\\=\frac{9}{10}[/tex]
d) Probability of at most one black ( BW or WW or WB)
[tex]=\frac{3}{5} \times \frac{2}{4} + \frac{2}{5} \times \frac{1}{4} + \frac{2}{5} \times \frac{3}{4}\\\\=\frac{6}{20} + \frac{2}{20} + \frac{6}{20} \\\\=\frac{14}{20}\\\\=\frac{7}{10}[/tex]
what is 2x + 4 = x + 40
[tex]{\boxed{\boxed { ⎆ Answer :- }}} \ [/tex]
[tex]2x + 4 = x + 40 \\ 2x - x = 40 - 4 \\ x = 36[/tex]
ʰᵒᵖᵉ ⁱᵗ ʰᵉˡᵖˢ ツ
꧁❣ ʀᴀɪɴʙᴏᴡˢᵃˡᵗ2²2² ࿐
In the diagram below, BC is an altitude of ABD. To the nearest whole unit, what is the length of CD?
Answer:
B. 23
Step-by-step explanation:
BC = 32
CA = 44
To find the length of CD, apply the altitude of right triangle formula, (altitude-on-hypotenuse theorem) which is given as:
h = √(xy)
Where,
h = CB = 32
x = CA = 44
y = CD = ?
Plug in the values
32 = √(44 × CD)
Square both sides
32² = 44 × CD
1,024 = 44 × CD
Divide both sides by 44
1,024/44 = CD
CD = 23 units (nearest whole unit)
the least value of x²-3x+5 is..
11/4
Step-by-step explanation:
to find the minimum value we require to find the vertex and determine if max/min
for a quadratic in standard form ; ax² + bx + c
the coordinate of the vertex is..
xvertex = -b/2a
x² - 3x + 5 is in standard form with a = 1,b = - 3 and c = 5
xvertex = - , -3/2 = 3/2
substitute this value into the equation for y-coordinate
yvertex = ( 3/2 ) ² -3 (3/2) + 5 = 11/4
vertex = ( 3/2, 11/4 )
to determine whether max/min
• if a > 0 then minimum u
• ifa < 0 then maximum n
here a = 1 > 0 hence minimum
minimum value of x² - 3x + 5 is 11/4
hope you understand this :)
A printing machine 600 books in 3 hours. How many books will the machine print in 5
Answer:
1, 000 hrs
Step-by-step explanation:
The machine prints,
in 3 hrs = 600 books
in 1 hr = 600/ 3 hrs = 200 hrs.
in 5 hrs = 200 × 5
= 1, 000 hrs
The printing machine will print 1000 books in 5 hours.
Let's calculate how many books the printing machine will print in 5 hours based on the given information.
To do this, we'll use the concept of rates and proportions.
Given that the printing machine can print 600 books in 3 hours, we can set up a rate equation as follows:
Rate of printing = Number of books / Time taken
Let "x" be the number of books the machine will print in 5 hours. We can set up the proportion:
600 books / 3 hours = x books / 5 hours
To solve for "x," we cross-multiply:
3 * x = 600 * 5
Now, let's solve for "x":
3x = 3000
x = 3000 / 3
x = 1000
So, the printing machine will print 1000 books in 5 hours.
Given: Printing machine prints 600 books in 3 hours.
Let the number of books the machine will print in 5 hours be "x."
Using the rate formula, we can set up the proportion:
600 books / 3 hours = x books / 5 hours
Cross-multiplying:
3 * x = 600 * 5
Solving for "x":
3x = 3000
x = 3000 / 3
x = 1000
Hence, the printing machine will print 1000 books in 5 hours.
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x - 3y +3=0
a) The length of the perpendicular drawn from the point (a, 3) on the line
3x + 4y + 5 = 0 is 4. Find the value of a.
Answer:
We know that for a line:
y = a*x + b
where a is the slope and b is the y-intercept.
Any line with a slope equal to -(1/a) will be perpendicular to the one above.
So here we start with the line:
3x + 4y + 5 = 0
let's rewrite this as:
4y = -3x - 5
y = -(3/4)*x - (5/4)
So a line perpendicular to this one, has a slope equal to:
- (-4/3) = (4/3)
So the perpendicular line will be something like:
y = (4/3)*x + c
We know that this line passes through the point (a, 3)
this means that, when x = a, y must be equal to 3.
Replacing these in the above line equation, we get:
3 = (4/3)*a + c
c = 3 - (4/3)*a
Then the equation for our line is:
y = (4/3)*x + 3 - (4/3)*a
We can rewrite this as:
y = (4/3)*(x -a) + 3
now we need to find the point where this line ( y = -(3/4)*x - (5/4)) and the original line intersect.
We can find this by solving:
(4/3)*(x -a) + 3 = y = -(3/4)*x - (5/4)
(4/3)*(x -a) + 3 = -(3/4)*x - (5/4)
(4/3)*x - (3/4)*x = -(4/3)*a - 3 - (5/4)
(16/12)*x - (9/12)*x = -(4/3)*a - 12/4 - 5/4
(7/12)*x = -(4/13)*a - 17/4
x = (-(4/13)*a - 17/4)*(12/7) = - (48/91)*a - 51/7
And the y-value is given by inputin this in any of the two lines, for example with the first one we get:
y = -(3/4)*(- (48/91)*a - 51/7) - (5/4)
= (36/91)*a + (153/28) - 5/4
Then the intersection point is:
( - (48/91)*a - 51/7, (36/91)*a + (153/28) - 5/4)
And we want that the distance between this point, and our original point (3, a) to be equal to 4.
Remember that the distance between two points (a, b) and (c, d) is:
distance = √( (a - c)^2 + (b - d)^2)
So here, the distance between (a, 3) and ( - (48/91)*a - 51/7, (36/91)*a + (153/28) - 5/4) is 4
4 = √( (a + (48/91)*a + 51/7)^2 + (3 - (36/91)*a + (153/28) - 5/4 )^2)
If we square both sides, we get:
4^2 = 16 = (a + (48/91)*a + 51/7)^2 + (3 - (36/91)*a - (153/28) + 5/4 )^2)
Now we need to solve this for a.
16 = (a*(1 + 48/91) + 51/7)^2 + ( -(36/91)*a + 3 - 5/4 + (153/28) )^2
16 = ( a*(139/91) + 51/7)^2 + ( -(36/91)*a - (43/28) )^2
16 = a^2*(139/91)^2 + 2*a*(139/91)*51/7 + (51/7)^2 + a^2*(36/91)^2 + 2*(36/91)*a*(43/28) + (43/28)^2
16 = a^2*( (139/91)^2 + (36/91)^2) + a*( 2*(139/91)*51/7 + 2*(36/91)*(43/28)) + (51/7)^2 + (43/28)^2
At this point we can see that this is really messy, so let's start solving these fractions.
16 = (2.49)*a^2 + a*(23.47) + 55.44
0 = (2.49)*a^2 + a*(23.47) + 55.44 - 16
0 = (2.49)*a^2 + a*(23.47) + 39.44
Now we can use the Bhaskara's formula for quadratic equations, the two solutions will be:
[tex]a = \frac{-23.47 \pm \sqrt{23.47^2 - 4*2.49*39.4} }{2*2.49} \\\\a = \frac{-23.47 \pm 12.57 }{4.98}[/tex]
Then the two possible values of a are:
a = (-23.47 + 12.57)/4.98 = -2.19
a = (-23.47 - 12.57)/4.98 = -7.23
3x=4(c-d)/d make d the subject
Answer:
[tex]d = \frac{4c}{3x + 4} [/tex]
Step-by-step explanation:
[tex]3x = \frac{4(c - d)}{d} [/tex]
Multiply both sides by d:
[tex]3xd = 4(c - d)[/tex]
Expand:
[tex]3xd = 4c \: - 4d[/tex]
+4d on both sides:
[tex]3xd + 4d = 4c[/tex]
Factorise d out of the left-hand side:
[tex]d(3x + 4) = 4c[/tex]
Divide both sides by (3x +4):
[tex]d = \frac{4c}{3x + 4} [/tex]
You want to send postcards to 15 friends. In the shop there are only 3 kinds of postcards. In how many ways can you send the postcards, if
Answer:
455 ways
Step-by-step explanation:
Given
[tex]n = 15[/tex] --- friends
[tex]r = 3[/tex] -- available postcard kinds
Required
Ways of sending the cards
The question is an illustration of combination and the formula is:
[tex]^nC_r = \frac{n!}{(n - r)!r!}[/tex]
So, we have:
[tex]^{15}C_3 = \frac{15!}{(15 - 3)!3!}[/tex]
[tex]^{15}C_3 = \frac{15!}{12!*3!}[/tex]
Expand
[tex]^{15}C_3 = \frac{15*14*13*12!}{12!*3*2*1}[/tex]
[tex]^{15}C_3 = \frac{15*14*13}{3*2*1}[/tex]
[tex]^{15}C_3 = \frac{2730}{6}[/tex]
[tex]^{15}C_3 = 455[/tex]
09:30 am - 4:30 pm minus 30 minutes?
Answer:
4:30
because 9:30 minus 4:30 = 5:00 and 5:00 minus 30 =4:30
WILL GIVE MOST BRAINIEST
Which of the following functions best describes this graph?
A. y (x + 4) (x + 5)
Answer:
D. y =
Step-by-step explanation:
The solutions to this graph (meaning when y equals 0 or when the graph crosses the x-axis) are 4 and 5.
The only answer choice that has the solutions 4 and 5 when you factor it out is D.
Here's the proof:
[tex]x^{2} -9x + 20[/tex]
Factors of 20: - 5 & -4
Sums that add up to -9: -5 + (-4)
[tex]x^{2} -4x-5x+20[/tex]
(factor the first two terms and the last two terms separately)
[tex](x^{2}-4x)(-5x+20)[/tex]
[tex]x(x-4) -5(x-4)[/tex]
(x - 5) (x - 4)
Hope it helps (●'◡'●)
Sam wants to build a unique pyramid bookend for his study. It's an oblique pyramid
with a right triangular base. The sides of the base are 3, 4, and 5 inches long. The
pyramid will fit exactly inside his bookshelf, which has a height of 18 inches. He
wishes to build the pyramid out of modeling clay. How many cubic inches of clay
does Sam need to buy?
36in^3
24in^3
62.8in^3
216in^3
Answer:
Volume of triangular pyramid = 36 inch³
Step-by-step explanation:
Given:
Sides of base triangle = 3, 4, 5 inches
Height of model = 18 inches
Find:
Volume of triangular pyramid
Computation:
Given base triangle is a right angle triangle
So,
Area of base = (1/2)(b)(h)
Area of base = (1/2)(3)(4)
Area of base = (1/2))(12)
Area of base = 6 inch²
Volume of triangular pyramid = (1/3)(Area of base)(Height of model)
Volume of triangular pyramid = (1/3)(6)(18)
Volume of triangular pyramid = 36 inch³
Jen recently rode her bicycle to visit her friend who lives 6 miles away. On her way there, her average speed was 8 miles per hour faster than on her way home. If jen
spent a total of 2 hours bicycling find the two rates.
the answer is in the picture above
Find the intersection of the parabola y=x^2+4x+3 and the line x-y=-1
Answer:
1
Step-by-step explanation:
Which ordered pairs are in the solution set of the system of linear inequalities?
y > Negative one-thirdx + 2
y < 2x + 3
On a coordinate plane, 2 straight lines are shown. The first solid line has a negative slope and goes through (0, 2) and (6, 0. Everything to the right of the line is shaded. The second dashed line has a positive slope and goes through (negative 3, negative 3) and (0, 3). Everything above the line is shaded.
Options:
(2, 2), (3, 1), (4, 2)
(2, 2), (3, –1), (4, 1)
(2, 2), (1, –2), (0, 2)
(2, 2), (1, 2), (2, 0)
Answer:
A. (2, 2), (3, 1), (4, 2)
Step-by-step explanation:
Given
[tex]y > -\frac{1}{3}x + 2[/tex]
[tex]y < 2x + 3[/tex]
Required
Solve for x and y
To solve this, we make use of graphical method (see attachment for graph)
All points that lie on the shaded region are true for the inequality
Next, we plot each of the given options on the graph
A. (2, 2), (3, 1), (4, 2)
All 3 points lie on the shaded region.
Hence, (a) is true
Answer:
A. (2, 2), (3, 1), (4, 2)
Step-by-step explanation:
what ordered pair makes both inequalities true
-3,5
-2,2
-1,-3
0,-1
Answer:
(-2, 2)
Step-by-step explanation:
(-2, 2) is the only ordered pair that makes both inequalities true.
Answer:
B
Step-by-step explanation:
got it right
Floataway Tours has $420,000 that can be use to purchase new rental boats for hire during the summer. The boats can be purchased from two different manufacturers. Floataway Tours would like to purchase at least 50 boats and would like to purchase the same number from Sleekboat as from Racer to maintain goodwill. At the same time,Floataway Tours wishes to have a total seating capacity of at least 200.
Required:
Formulate this problem as a linear program.
Answer and explanation:
A linear problem is an equation based on known and unknown variables that follow a linear path, usually without exponents and look like this:
y=mx+b. To formulate the linear constraints of the problem above, we look at the unknown variables and known variables and define and equation using this.
From the problem, assume x and y are the prices of the different boat brands:
50x+50y=420000
Assume a and b are number of x brand boats and y brand boats supplied thus:
a+b>=200
Solve, then check algebraically and graphically. 9x-3=78
Answer:
[tex]9x - 3 = 78 \\ 9x - 3 + 3 = 78 + 3 \\ 9x = 81 \\ \frac{9x}{9} = \frac{81}{9} \\ x = 9[/tex]
Answer:
[tex]9x - 3 = 78 \\9 x = 78 + 3 \\ 9x = 81 \\ x = \frac{81}{9} \\ x = 9[/tex]
Mrs. Rodger got a weekly raise of $145. If she gets paid every other week, write an integer describing how the raise will affect her paycheck.
Answer:
her salary will increase by $ 145 for every week
Step-by-step explanation:
x=1st paycheck (integer).
weekly raise = $ 145.
After completing the 1st week she will get $ (x+145).
Similarly after completing the 2nd week she will get
$ (x + 145) + $ 145.
= $ (x + 145 + 145)
= $ (x + 290)
So in this way end of every week her salary will increase by $ 145.
Janie can stuff 30 envelops in one minute. Find an expression for the number of envelopes she can stuff in n hours?
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.
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
1. Suppose half of all newborns are girls and half are boys. Hospital A, a large city hospital, records an average of 50 births a day. Hospital B, a small, rural hospital, records an average of 10 births a day. On a particular day, which hospital is less likely to record 80% or more female births?
Answer:
5%
Step-by-step explanation:
Hospital A (with 50 births a day), because the more births you see, the closer the proportions will be to 0.5.
Hospital B (with 10 births a day), because with fewer births there will be less variability.
The two hospitals are equally likely to record such an event, because the probability of a boy does not depend on the number of births
Two hospitals have an equal chance of recording such an event.
What is probability?The area of mathematics known as probability deals with numerical representations of the likelihood that an event will occur or that a statement is true. An event's probability is a number between 0 and 1, where, roughly speaking, 0 denotes the event's impossibility and 1 denotes certainty.
Given
Hospital A (with 50 births per day), as the proportions will be closer to 0.5 the more births you see.
Hospital B (with 10 births per day), thus there will be less unpredictability with fewer births.
Due to the fact that the likelihood of a boy does not rely on the number of births, the two hospitals have an equal chance of recording such an event.
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I need help with this problem.
Answer:
-4
Step-by-step explanation:
2t=-1-7
t=-8/2
t=-4
i am not sure also
At what x value does the function given below have a hole?
f(x)=x+3/x2−9
Answer:
hole at x=-3
Step-by-step explanation:
The hole is the discontinuity that exists after the fraction reduces. (Still doesn't exist for original of course)
The discontinuities for this expression is when the bottom is 0. x^2-9=0 when x=3 or x=-3 since squaring either and then subtracting 9 would lead to 0.
So anyways we have (x+3)/(x^2-9)
= (x+3)/((x-3)(x+3))
Now this equals 1/(x-3) with a hole at x=-3 since the x+3 factor was "cancelled" from the denominator.
find the Maclaurin series for f(x) using the definition of a Maclaurin series. [Assume that f has a power series expansion. Do not show that Rn(x) → 0.] Find the associated radius of convergence R. f(x) = 6(1 − x)−2 Step 1 The Maclaurin series formula is f(0) + f '(0)x + f ''(0) 2! x2 + f '''(0) 3! x3 + f (4)(0) 4! x4 + .
Answer:
= ∑ 6*n*x^n-1
Radius of convergence = 1
Step-by-step explanation:
f(x) = 6(1-x)^-2
Maclaurin series can be expressed using the formula
f(x) = f(0) + f '(0)x + f ''(0)/ 2! (x)^2 + f '''(0)/3! (x)^3 + f (4)(0) 4! x4 + .
attached below is the detailed solution
Radius of convergence = 1
The Maclaurin series for f(x) = 6 / (1 - x )^2 = ∑ 6*n*x^n-1 ( boundary ; ∞ and n = 1 )
Evaluate the given expression for x=7.
8x +9
The answer is ---
Answer:
The answer is 65
Step-by-step explanation:
Evaluate:
8x + 9
When x = 7
Use PEMDAS order of operations:
8x + 9
= 8(7) + 9
= 56 + 9
= 65
Hope this helps
A statistician calculates that 7% of Americans are vegetarians. If the statistician is correct, what is the probability that the proportion of vegetarians in a sample of 403 Americans would differ from the population proportion by more than 3%
Answer:
0.0182 = 1.82% probability that the proportion of vegetarians in a sample of 403 Americans 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 statistician calculates that 7% of Americans are vegetarians.
This means that [tex]p = 0.07[/tex]
Sample of 403 Americans
This means that [tex]n = 403[/tex]
Mean and standard deviation:
[tex]\mu = p = 0.07[/tex]
[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.07*0.93}{403}} = 0.0127[/tex]
What is the probability that the proportion of vegetarians in a sample of 403 Americans would differ from the population proportion by more than 3%?
Proportion below 7 - 3 = 4% or above 7 + 3 = 10%. Since the normal distribution is symmetric, these probabilities are equal, which means that we find one of them, and multiply by 2.
Probability the proportion is below 4%
p-value of Z when X = 0.04.
[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}{0.0127}[/tex]
[tex]Z = -2.36[/tex]
[tex]Z = -2.36[/tex] has a p-value of 0.0091
2*0.0091 = 0.0182
0.0182 = 1.82% probability that the proportion of vegetarians in a sample of 403 Americans would differ from the population proportion by more than 3%.