Answer:
0.8665 = 86.65% probability that the sample proportion of Democrats will be greater than 52%.
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]
Suppose 54% of the registered voters in a country are Democrats. Sample of 770.
This means that:
[tex]p = 0.54, s = \sqrt{\frac{0.54*0.46}{770}} = 0.01796[/tex]
What is the probability that the sample proportion of Democrats will be greater than 52%?
This is 1 subtracted by the p-value of Z when X = 0.52. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{0.52 - 0.54}{0.01796}[/tex]
[tex]Z = -1.11[/tex]
[tex]Z = -1.11[/tex] has a p-value of 0.1335
1 - 0.1335 = 0.8665
0.8665 = 86.65% probability that the sample proportion of Democrats will be greater than 52%.
hi my name is stephanie
Answer:
hello...................
Answer:
hello :)
Step-by-step explanation:
Given the vectors w = <-5, 3> and z = <1, 4>, find the results of the vector subtractions.
Answer:
Given two linearly independent vectors w and z
We want -w-z
Hence apply a negative gradient to w
w=-<-5,3> =<5,-3>
So <5,-3>-<1,4> = (<5-1>,<-3-4>)
The answer is <4,-7>
What is the y-intercept of the line your equation X-1/2Y = -6
A.-6
B.-3
C.0
D.12
9514 1404 393
Answer:
D. 12
Step-by-step explanation:
Set x=0 and solve for y.
0 -1/2y = -6
y = (-2)(-6) = 12 . . . . . . multiply by -2 to clear the fraction
The y-intercept is 12.
You bought a shirt with the price of $135.50, and the sale tax rate is 8.25% ___Find the sale tax
Answer:
tax is 11.50 tax and price is 147
Step-by-step explanation:
you would do 135.50 times 8.25% to find the tax which is estimated to $11.50 if you wanted to find the tax and the price you do $135.50 plus $11.50 which is $147
Ill give brainliest
Answer:
is 4 an option?
Step-by-step explanation:
I think it is 4
What is the slope of the line graphed below?
Answer:
2/3
Step-by-step explanation:
rise over run
The lower the standard error: Multiple Choice the more precisely the parameter estimates the true values. the less confident the manager can be that the parameter estimates reflect the true values. the less precisely the parameter estimates the true values. the more confident the manager can be that the parameter estimates reflect the true values.
Answer:
The more confident the manager can be that the parameter estimates reflect the true values.
Step-by-step explanation:
Standard error:
The standard error is a parameter that is direct proportional to the margin of error of a confidence interval, that is, the higher the standard error, the higher the margin of error of the confidence interval.
A lower margin of error leads to a more precise interval, thus, a lower standard error will also mean a higher confidence for the estimate, and thus, the correct option is:
The more confident the manager can be that the parameter estimates reflect the true values.
In the figure shown below, m 2C = 40° and AB = 8. Which equation could be used to find x?
A
8
400
BO
Х
с
Answer:
[tex]x = 8\tan(50)[/tex]
Step-by-step explanation:
Given
The attached triangle
Required
Find x
To find x, we make use of the following trigonometry ratio;
[tex]\tan(\theta) = \frac{Opposite}{Adjacent}[/tex]
So, we have:
[tex]\tan(50) = \frac{x}{8}[/tex]
Make x the subject
[tex]x = 8\tan(50)[/tex]
The data below shows the grams of fat for a variety of snacks. Morris wants to calculate the standard error of the sample mean for this set of data. Snack Grams of Fat Snack 1 9 Snack 2 13 Snack 3 21 Snack 4 30 Snack 5 31 Snack 6 31 Snack 7 34 Snack 8 25 Snack 9 28 Snack 10 20 What is the standard error for this set of data
Answer:
the standard error of data set is 2.628
Step-by-step explanation:
Given the data in the question;
set;
x = 9, 13, 21, 30, 31, 31, 34, 25, 28, 20
To get the standard of Error for this data set, we use the formual
S.E = s / √n
First we determine the mean average;
Mean x' = ∑x / n = ( 9 + 13 + 21 + 30 + 31 + 31 + 34 + 25 + 28 + 20 ) / 10
x' = 242 / 10
Mean x' = 24.2
Next we find the standard deviation s:
x (x-x')²
9 231.04
13 125.44
21 10.24
30 33.64
31 46.24
31 46.24
34 96.04
25 0.64
28 14.44
20 17.64
Total ∑(x-x')² = 621.6
so Variance = ∑(x-x')² / (n-1) = 621.6 / ( 10 - 1 ) = 621.6 / 9
Variance = 69.0667
Standard deviation S = √Variance
Standard deviation S = √69.0667
Standard deviation S = 8.3106
So we substitute into our formula to get the standard of error;
S.E = 8.3106 / √10
S.E = 2.628
Therefore, the standard error of data set is 2.628
Answer:
2.63
Step-by-step explanation:
A train traveled for T = 2.0 hours at a constant speed of R = 36 miles per hour. Use the formula D = R · T to find the total distance the train traveled (in miles). Do not include the units in your answer.
Answer: T=1700
Step-by-step explanation:
You buy halibut at 28 per pound. One portion of seared halibut requires 6 ounces of halibut. How much dose the halibut for one portion cost?
Answer:
4.6
Step-by-step explanation:
yes
PLEASE HELP ME I DOnT KNOW THIS
Answer:
y=25*2ˣ.
Step-by-step explanation:
no details.
The manager of a pizza chain in Albuquerque, New Mexico, wants to determine the average size of their advertised 13-inch pizzas. She takes a random sample of 37 pizzas and records their mean and standard deviation as 13.50 inches and 1.90 inches, respectively. She subsequently computes the 95% confidence interval of the mean size of all pizzas as [12.89, 14.11]. However, she finds this interval to be too broad to implement quality control and decides to reestimate the mean based on a bigger sample. Using the standard deviation estimate of 1.90 from her earlier analysis, how large a sample must she take if she wants the margin of error to be under 0.5 inch
Answer:
She must take a sample of 56.
Step-by-step explanation:
We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:
[tex]\alpha = \frac{1 - 0.95}{2} = 0.025[/tex]
Now, we have to find z in the Z-table as such z has a p-value of [tex]1 - \alpha[/tex].
That is z with a pvalue of [tex]1 - 0.025 = 0.975[/tex], so Z = 1.96.
Now, find the margin of error M as such
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.
Standard deviation estimate of 1.90
This means that [tex]\sigma = 1.9[/tex]
Wow large a sample must she take if she wants the margin of error to be under 0.5 inch?
This is n for which M = 0.5. So
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
[tex]0.5 = 1.96\frac{1.9}{\sqrt{n}}[/tex]
[tex]0.5\sqrt{n} = 1.96*1.9[/tex]
[tex]\sqrt{n} = \frac{1.96*1.9}{0.5}[/tex]
[tex](\sqrt{n})^2 = (\frac{1.96*1.9}{0.5})^2[/tex]
[tex]n = 55.5[/tex]
Rounding up:
She must take a sample of 56.
Dena borrowed $75,000 to buy a used car. The credit union charged 9% simple interest per year. She paid $2,025 in interest. For what period of time did she borrow the money?
Whats the...
Principal_____
Rate____
Intrest_____
anyone know the missing angle ?
Answer:48.013
Step-by-step explanation: just found it
Find all Values of b that will make the polynomial a perfect square trinomial.
25z^2+bz+36
Please write out how to do this so I can see the steps of what I am doing wrong. thank you!
Answer:
There are two solutions for [tex]b[/tex]: [tex]b = + 30\cdot z[/tex], [tex]b = -30\cdot z[/tex]
Step-by-step explanation:
By Algebra, we know that a polynomial is a perfect square trinomial if it is of the form:
[tex]a^{2} + 2\cdot a \cdot c + c^{2} = (a + c)^{2}[/tex] (1)
By direct comparison, we have the following system:
[tex]a^{2} = 25\cdot z^{2}[/tex], [tex]c^{2} = 36[/tex], [tex]2\cdot a \cdot c = b[/tex].
There are two possible solutions for [tex]b[/tex]:
1) [tex]a = \pm 5\cdot z[/tex], [tex]c = \pm 6[/tex], [tex]b = + 30\cdot z[/tex]
2) [tex]a = \pm 5\cdot z[/tex], [tex]c = \mp 6[/tex], [tex]b = -30\cdot z[/tex]
2logb - 3logb = log8b - log4b
Answer:
b=1/2
Step-by-step explanation:
2logb - 3logb = log8b - log4b
log[tex]b^{2}[/tex] - log[tex]b^{3}[/tex] = log8b - log4b
log([tex]\frac{1}{b}[/tex]) = log(2)
∴1/b = 2
∴b = 1/2
Use the graph to answer the questions.
1) write into vertex form.
2) identify the vertex, focus, and directrix.
Answer:
y = 2( x+5)^2 -4
Vertex (-5,-4)
directrix y = -33/8
focus (-5, -31/8)
Step-by-step explanation:
First identify the vertex, which is the minimum
Vertex = (-5,-4)
The vertex form is y = a( x-h)^2 + k
y = a( x- -5)^2 -4
y = a( x+5)^2 -4
We need to determine a
Substitute a point on the graph
(-3,4) is on the graph
4 = a( -3+5)^2 -4
4 = a( 2)^2 -4
4 = 4a -4
Add 4 to each side
8 = 4a
Divide by 4
8/4 = a
a=2
y = 2( x+5)^2 -4
To find the focus and directrix, write in standard form
4p(y-k)=(x-h)^2
y+4 = 2(x+5)^2
1/2 (y+4) = (x+5)^2
4p = 1/2
p = 1/8
The focal length is 1/8
Subtract this from the y coordinate to get the directrix
y = -4 -1/8
y = -32/8 - 1/8 = -33/8
Add this to the y coordinate to get the coordinate for the focus the x coordinate the same
(-5, -4+1/8)
(-5, -32/4+1/8)
(-5, -31/8)
find the value of x (URGENT/GIVING BRAINLIEST)
Answer:
B) 24
Step-by-step explanation:
Those are alternate interior angle which mean they are congruent or equal to each other
2x=48 divide
48÷2=24
Answer:
B) 24
step by step:
2x = 48 ( two straight lines are parallel forming and the internal stagger angle is equal)
Can anyone solve this?
If square C is 64 in^2, then its dimensions are 8 x 8.
If square D is 81 in^2, then its dimensions are 9 x 9.
Since D is bigger than C and I sits in that extra space, then the dimensions of I are 1 x 1.
Since H is smaller than C, specifically I smaller, than its dimensions are 7 x 7.
Then, H and C make up one side of B, so 7 + 8 = 15. The dimensions of B are 15 x 15.
Since E is bigger than D by I, then the dimensions of E are 10 x 10.
If we find the length of the right side (B + C + D), which is 15 + 8 + 9 = 32, then we know that F + E + D must also add up to 32. F + 10 + 9 = 32 || F = 13. The dimensions of F are 13 x 13.
Then, F is E + G, so 13 = 10 + G. G = 3. The dimensions of G are 3 x 3.
Lastly, since we know the side length of the whole square is 32, then A + F must equal 32. 32 = A + 13. A = 19. The dimensions of A are 19 x 19.
A = 19 x 19 = 361 in^2
B = 15 x 15 = 225 in^2
C = 8 x 8 = 64 in^2
D = 9 x 9 = 81 in^2
E = 10 x 10 = 100 in^2
F = 13 x 13 = 169 in^2
G = 3 x 3 = 9 in^2
H = 7 x 7 = 49 in^2
I = 1 x 1 = 1 in^2
Hope this helps!! :)
The area of a rectangle is represented by 12n2 - 19n - 21. If the width is 3n - 7, which expression represents the perimeter?
A. 7n - 4
B. 7n+4
C. 14n -8
D. 14n +8
Answer:
C 14n - 8
Step-by-step explanation:
rectangle area = length×width = 12n²-19n-21
width = 3n-7
what do we need to multiply with width to get the full area expression ?
think : what do we need to multiply with 3n to get 12n² (4n)?
and what to multiply with -7 to get -21 (3)?
=> length = 4n+3
perimeter is 2×length + 2×width
p = 2(3n-7) + 2(4n+3) = 6n-14+8n+6 = 14n-8
Factorise 5x + 10=
ᴘʟᴀʏɪɴɢ: Who Asked (Feat: Nobody did ) ───────────⚪────── ◄◄⠀▐▐⠀►:/:⠀───○
Answer:
5(x+2)
Step-by-step explanation:
5x + 10=
Factor out 5
5(x+2)
Answer:
[tex]5(x + 2)[/tex]
Step-by-step explanation:
Get 5 out
[tex]5x + 10 \\ 5(x + 2)[/tex]
Questlon 18 of 25
Joanne and Betty have a combined age of 41 years. If Joanne is 17 years old,
how old is Betty?
Answer here
SUBMIT
Answer:
24
Step-by-step explanation:
betty age = 41 - 17
= 24
Help me plz I’m too slow for this
Answer:
160 units²
Step-by-step explanation:
Surface area of the square pyramid = a² + 2al
Where,
a = side length of the square = 8
l = slant height of the triangular face = 6
Plug in the values
Surface area of the square pyramid = 8² + 2*8*6
= 64 + 96
= 160 units²
You randomly draw a marble from a bag of marbles that contains 888 blue marbles, 555 green marbles, and 888 red marbles.
Answer:
whats the question?
Step-by-step explanation:
Solve for x 11^x/11^3=11^2 PPEASE I HAVE AN F
Check all of the correct names for the object pictured below.
Answer:
VU,UV, and probably VU just pick 3 answers cause there is 6 questions in all but i hope these answers help u have a nice day too.
Step-by-step explanation:
। Find the H.C. F. of :
x2+ 2xy+y and 3ax+3ay
Answer:
Factorizing 4x2 - 9y2, we get
(2x)2 - (3y)2, by using the identities of a2 - b2.
= (2x + 3y) (2x - 3y)
Step-by-step explanation:
f(x) = 3x + 4 is y =
The manager of a new supermarket wished to estimate the likely expenditure of his customers. A sample of till slips from a similar supermarket describing the weekly amount spent by 500 randomly selected customers was collected and analysed. This expenditure was found to be approximately normally distributed with a mean of $50 and a standard deviation of $15.
Find the probability that any shopper selected at random spends more than $80 per week?
Find the percentage of shoppers who are expected to spend between $30 and 80 per week?
Answer:
0.0228 = 2.28% probability that any shopper selected at random spends more than $80 per week.
88.54% of shoppers are expected to spend between $30 and 80 per week.
Step-by-step explanation:
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.
Normally distributed with a mean of $50 and a standard deviation of $15.
This means that [tex]\mu = 50, \sigma = 15[/tex]
Find the probability that any shopper selected at random spends more than $80 per week?
This is 1 subtracted by the p-value of Z when X = 80. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{80 - 50}{15}[/tex]
[tex]Z = 2[/tex]
[tex]Z = 2[/tex] has a p-value of 0.9772
1 - 0.9772 = 0.0228
0.0228 = 2.28% probability that any shopper selected at random spends more than $80 per week.
Find the percentage of shoppers who are expected to spend between $30 and 80 per week?
The proportion is the p-value of Z when X = 80 subtracted by the p-value of Z when X = 30.
X = 80
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{80 - 50}{15}[/tex]
[tex]Z = 2[/tex]
[tex]Z = 2[/tex] has a p-value of 0.9772
X = 30
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{30 - 50}{15}[/tex]
[tex]Z = -1.33[/tex]
[tex]Z = -1.33[/tex] has a p-value of 0.0918
0.9772 - 0.0918 = 0.8854
0.8854*100% = 88.54%
88.54% of shoppers are expected to spend between $30 and 80 per week.
