On the Navajo Reservation, a random sample of 210 permanent dwellings in the Fort Defiance region showed that 69 were traditional Navajo hogans. In the Indian Wells region, a random sample of 162 permanent dwellings showed that 22 were traditional hogans. Let p1 be the population proportion of all traditional hogans in the Fort Defiance region, and let p2 be the population proportion of all traditional hogans in the Indian Wells region.
Required:
a. Find a 99% confidence interval for p 1 - P2.
b. Examine the confidence interval and comment on its meaning. Does it include numbers that are all positive?
Answer:
a) The 99% confidence interval for the difference of proportions is (0.0844, 0.3012).
b) We are 99% sure that the true difference in proportions is between 0.0844 and 0.3012. Since all values are positive, there is significant evidence at the 1 - 0.99 = 0.01 significance level to conclude that the proportion is the Fort Defiance region is higher than in the Indian Wells region.
Step-by-step explanation:
Before finding the confidence interval, we need to understand the central limit theorem and subtraction of normal variables.
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]
Subtraction between normal variables:
When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.
Fort Defiance:
69 out of 210, so:
[tex]p_1 = \frac{69}{210} = 0.3286[/tex]
[tex]s_1 = \sqrt{\frac{0.3286*0.6714}{210}} = 0.0324[/tex]
Indian Wells:
22 out of 162, so:
[tex]p_2 = \frac{22}{162} = 0.1358[/tex]
[tex]s_2 = \sqrt{\frac{0.1358*0.8642}{162}} = 0.0269[/tex]
Distribution of the difference:
[tex]p = p_1 - p_2 = 0.3286 - 0.1358 = 0.1928[/tex]
[tex]s = \sqrt{s_1^2+s_2^2} = \sqrt{0.0324^2 + 0.0269^2} = 0.0421[/tex]
a. Find a 99% confidence interval for p1 -p2.
The confidence interval is:
[tex]p \pm zs[/tex]
In which
z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].
99% confidence level
So [tex]\alpha = 0.01[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.01}{2} = 0.995[/tex], so [tex]Z = 2.575[/tex].
The lower bound of the interval is:
[tex]p - zs = 0.1928 - 2.575*0.0421 = 0.0844[/tex]
The upper bound of the interval is:
[tex]p + zs = 0.1928 + 2.575*0.0421 = 0.3012[/tex]
The 99% confidence interval for the difference of proportions is (0.0844, 0.3012).
Question b:
We are 99% sure that the true difference in proportions is between 0.0844 and 0.3012. Since all values are positive, there is significant evidence at the 1 - 0.99 = 0.01 significance level to conclude that the proportion is the Fort Defiance region is higher than in the Indian Wells region.
Find the value of [(33.7)² - (15.3)²]^½ leaving your answer correct to 4 significant figures
Answer:
30.03
Step-by-step explanation:
[(33.7)² - (15.3)²]^½
= [1135.69 - 234.09]^½
= [901.6]^½
= 30.02665483
= 30.03 (4sf)
How can you create and graph a piecewise function that has restrictions on the domain?
Answer:
Use inequalities.
At certain x values.
Step-by-step explanation:
[tex]3 \leqslant x \leqslant 6[/tex]
[tex] - \infty < x < \infty [/tex]
[tex]x = 6[/tex]
A vending machine dispenses coffee into a twenty-ounce cup. the amount of coffee dispensed into the cup is normally distriubuted with a standard deviation of 0.03 ounce. You can allow the cup to overfill 2% of the time. What amount should you set as the mean amount of coffee to be dispensed?
Answer:
x=20.938
Step-by-step explanation:
-2.053748911 = (x - 21)/.03
x=20.938
Need helpppp ! tyyy
Answer:
63°
Step-by-step explanation:
Both angle 3 and 2 are equal because of the property of vertically opposite angles.Given the following coordinates complete the glide reflection transformation.
Answer:
[tex]A" = (7,-2)[/tex]
[tex]B" = (10,0)[/tex]
[tex]C"= (12,-3)[/tex]
Step-by-step explanation:
Given
[tex]A = (4,2)[/tex]
[tex]B = (7,0)[/tex]
[tex]C =(9,3)[/tex]
a: Reflect over x-axis
The rule of this is:
[tex](x,y) \to (x,-y)[/tex]
So, we have:
[tex]A' = (4,-2)[/tex]
[tex]B' = (7,0)[/tex]
[tex]C' = (9,-3)[/tex]
b: Shift 3 units left
The rule of this is:
[tex](x,y) \to (x+3,y)[/tex]
So, we have:
[tex]A" = (4+3,-2)[/tex]
[tex]A" = (7,-2)[/tex]
[tex]B" = (7+3,0)[/tex]
[tex]B" = (10,0)[/tex]
[tex]C"= (9+3,-3)[/tex]
[tex]C"= (12,-3)[/tex]
a new automobile cost 11300 which is 100 more than 25 times a certain number what is the number
Answer:
The number is 448.
Step-by-step explanation:
Hope it helps
Which confidence level would produce the widest interval when estimating the mean of a population from the mean and standard deviation of a sample of that population?
Answer:
54% ...
Step-by-step explanation:
this is the answer I guess
The confidence level that produces the widest interval is the one with the highest percentage, which is 54%.
Option B is the correct answer.
What is z-score?A z-score also called a standard score is a measure of how many standard deviations a data point is away from the given mean of a distribution.
It measures the unusual or extreme a particular data point is compared to the rest of the distribution
We have,
The width of a confidence interval is proportional to the critical value of the corresponding confidence level.
The critical value is determined by the standard normal distribution or t-distribution, depending on the sample size and whether the population standard deviation is known.
In general,
The wider the confidence interval, the less precise the estimate of the population means.
Therefore, we want to choose the confidence level that produces the widest interval, which corresponds to the largest critical value.
For a given sample size,
The critical value increases as the confidence level increases.
For example, the critical value for a 95% confidence level is larger than the critical value for a 90% confidence level.
Therefore,
The confidence level that produces the widest interval is the one with the highest percentage, which is 54%.
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What is the mean of 86, 80, and 95
87 is the mean.
To find the mean, you must
- add all of the numbers
- divide by the amount of numbers given
In this case, you would want to do (86 + 80 + 95)/3. This would give you an answer of 87.
Please helps fill in the charts
A and b
With order of pairs
Answer:
...
Step-by-step explanation:
seeee the above picture
This table shows how many male and female students attended two different
movies.
What is the probability that a randomly chosen person from this group is male
and attended an action movie?
Round your answer to two decimal places.
Action
Drama
Total
Mala
105
124
229
Female
99
151
250
Total
204
275
479
A. 0.11
B. 0.43
Ο Ο Ο Ο
C. 0.22
D. 0.52
Answer:
Male & action movie among a group of total 479
Step-by-step explanation:
We only choose male from action movie category so:
p = 105/ 479 = 0.22
The probability that a randomly chosen person from this group is male and attended an action movie will be 0.22. Then the correct option is C.
What is probability?Its basic premise is that something will almost certainly happen. The percentage of favorable events to the total number of occurrences.
This table shows how many male and female students attended two different movies.
Action Drama Total
Mala 105 124 229
Female 99 151 250
Total 204 275 479
Then the probability that a randomly chosen person from this group is male and attended an action movie will be
Favorable event = 105
Total event = 479
Then the probability will be
P = 105 / 479
P = 0.219
P ≈ 0.22
Then the correct option is C.
More about the probability link is given below.
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A canoeist paddled down a river a distance of 2 miles in 45 minutes. Paddling up-stream on his return, it took him 90 minutes. Find the rate of the canoe in still water.
ASAP! Plssssss
Tysm.
Answer:
4×10⁶ is the answer.........
Answer:
[tex]4 \times {10}^{6} [/tex]
Step-by-step explanation:
[tex] \frac{8 \times {10}^{24} }{2 \times {10}^{18} } [/tex]
[tex] \frac{4 \times {10}^{24} }{ {10}^{18} } [/tex]
[tex] = 4 \times {10}^{6} [/tex]
I need help completing this problem ASAP
Answer:
It is E. radicand
Step-by-step explanation:
Answer:
Radicand
Step-by-step explanation:
Radicand is the number found inside the radicals
Example:
[tex]\sqrt[4]{5} ; 2\sqrt[4]{5}[/tex] are like terms
5 -> radicand and 4 is the index
Dogsled drivers, known as mushers, use several different breeds of dogs to pull their sleds. One proponent of Siberian Huskies believes that sleds pulled by Siberian Huskies are faster than sleds pulled by other breeds. He times 47 teams of Siberian Huskies on a particular short course, and they have a mean time of 5.2 minutes. The mean time on the same course for 39 teams of other breeds of sled dogs is 5.5 minutes. Assume that the times on this course have a population standard deviation of 1.4 minutes for teams of Siberian Huskies and 1.1 minutes for teams of other breeds of sled dogs. Let Population 1 be sleds pulled by Siberian Huskies and let Population 2 be sleds pulled by other breeds. Step 1 of 2 : Construct a 95% confidence interval for the true difference between the mean times on this course for teams of Siberian Huskies and teams of other breeds of sled dogs
Answer:
The 95% confidence interval for the true difference between the mean times on this course for teams of Siberian Huskies and teams of other breeds of sled dogs is (-0.8276, 0.2276).
Step-by-step explanation:
Before building the confidence interval, we need to understand the central limit theorem and subtraction of normal variables.
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.
Subtraction between normal variables:
When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.
Siberian Huskies:
Sample of 47, mean of 5.2 minutes, standard deviation of 1.4. So
[tex]\mu_1 = 5.2[/tex]
[tex]s_1 = \frac{1.4}{\sqrt{47}} = 0.2042[/tex]
Others:
Sample of 39, mean of 5.5 minutes, standard deviation of 1.1. So
[tex]\mu_2 = 5.5[/tex]
[tex]s_2 = \frac{1.1}{\sqrt{39}} = 0.1761[/tex]
Distribution of the difference:
[tex]\mu = \mu_1 - \mu_2 = 5.2 - 5.5 = -0.3[/tex]
[tex]s = \sqrt{s_1^2+s_2^2} = \sqrt{0.2042^2+0.1761^2} = 0.2692[/tex]
Confidence interval:
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 = zs[/tex]
In which s is the standard error. So
[tex]M = 1.96(0.2692) = 0.5276[/tex]
The lower end of the interval is the sample mean subtracted by M. So it is -0.3 - 0.5276 = -0.8276.
The upper end of the interval is the sample mean added to M. So it is -0.3 + 0.5276 = 0.2276
The 95% confidence interval for the true difference between the mean times on this course for teams of Siberian Huskies and teams of other breeds of sled dogs is (-0.8276, 0.2276).
Wesley is making a patio from stones of two sizes, 5 inch wide and 10 inch wide. He wants to begin and end his pattern with a 10 inch stone so there will be one more of the 10 inch stones than of 5inch stones. His patio will be 130 inches wide.
How many 10 inch stones will Wesley need for one row?
9514 1404 393
Answer:
9
Step-by-step explanation:
If x is the number of 10-inch stones, then (x-1) is the number of 5-inch stones, and the total width is ...
10x +5(x-1) = 130
15x -5 = 130 . . . . . . . eliminate parentheses
15x = 135 . . . . . . add 5
x = 9 . . . . . . . divide by 15
Wesley will need 9 10-inch stones for one row.
z/3 - 4(z-1) = 5(z-2)+1
What is the value of z?
Answer: [tex]\frac{3}{2}[/tex]
Step-by-step explanation:
First, we need to open the brackets on either side of the equation.
[tex]\frac{z}3}[/tex] - 4z+4 = 5z-10+1
After opening the brackets, we need to separate the variables from the constants.
[tex]\frac{z}{3}[/tex] -4z-5z = -10+1-4
Then we need to convert the variable fraction into a normal variable by multiplying the variable fraction and also all other terms in the equation.
3([tex]\frac{z}{3}[/tex]) 3(-4z) 3(-5z) = 3(-10) + 3(1) + 3(-4)
z -12z -15z = -30+3-12
Now, we can simplify the equation !
-26z = -39
z = -39÷-26
= [tex]\frac{3}{2}[/tex]
PLEASE HELP!!!!!!!!!!!!!!!! (answer in decimal!!!!!!!!)
9514 1404 393
Answer:
0.75
Step-by-step explanation:
You know that ...
P(S or T) = P(S) +P(T) -P(S and T)
When events are mutually exclusive, P(S and T) = 0. Then ...
P(S or T) = 5/8 + 1/8 = 6/8 = 3/4
P(S or T) = 0.75
18. The function f(x) = 4x - 8 is reflected across the y-axis, resulting in a new
function, g(x). Write the equation of g(x).
Please explain the steps!! ❤️
The equation of the reflected function across the y-axis is g(x) = -4x - 8.
What is a function?A statement, principle, or policy that creates the link between two variables is known as a function. Functions are found all across mathematics and are required for the creation of complex relationships.
The function f(x) = 4x - 8 is reflected across the y-axis.
The function g(x) will be given by putting the negative x in place of x. Then the reflected function is obtained.
g(x) = -4x - 8
Then the equation of the reflected function across the y-axis is g(x) = -4x - 8.
The graph of the reflected graph is given below.
More about the function link is given below.
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Let sin A = -3/5
with 270°
sinA/2
Answer:
-0.316227766
Step-by-step explanation:
0.316227766
help. WORTH 15 POINTS!!!
Answer:
x=27
Step-by-step explanation:
The sum of the angles of a triangle are 180 degrees
90 + x+15 + 2x-6 = 180
Combine like terms
3x+99=180
Subtract 99 from each side
3x+99-99=180-99
3x =81
Divide each side by 3
3x/3 = 81/3
x=27
Please help me with this question
Answer:
The sum of 1/6 and 1/7 would be 13/42, or, if you wanted the answer in decimal form rounded to the nearest hundredth, it would be about 0.31.
To find the sum of 1/6 and 1/7, we cannot simply add the numerators together and maintain the same denominator. This is because 1/6 and 1/7 have different denominators, so we don't know which denominator to maintain!
To fix this we need to find a number that is divisible by both 6 and 7. One easy way to do this is to multiply the two numbers together:
6 x 7 = 42
If we were to change the denominator to 42 for each fraction, we could add the numerators together and maintain a denominator of 42. However, this means we must change the numerator of each fraction along with its denominator.
Let's start with 1/6. We can multiply 6 by 7 to obtain 42, but this means we also have to multiply 1 by 7 to keep the fraction proportionate. If the fraction does not maintain the same proportion, it will be a completely different fraction!
We know that 1 x 7 = 7, so it is safe to say that 1/6 is equal to 7/42.
We can apply the same logic to 1/7. Since 7 x 6 is 42 we need to multiply 1 by 6 along with 7. Note: you cannot multiply each number by 7 this time, because 7 x 7 would be 49, not 42. In multiplying the numerator and denominator by 6 we know that 1/7 = 6/42.
Now we have an equation of:
6/42 + 7/42
Now we can add it as we would normally by adding the numerators and keeping the denominator to get:
6/42 + 7/42 = 13/42
If you needed the answer in decimal form it would be about 0.3095238095, or 0.31 rounded to the nearest hundredth.
I hope this helped.
The weight (in pounds) and height (in inches) for a child were measured every few months over a two-year period. The measurements are given in the table.
Using technology, what is the equation for the least-squares regression line?
y= –34.13 1.98x
y = 1.98 – 34.13x
y = 17.37 0.50x
y = 0.50 17.37x
I think it's (C) y = 17.37 0.50x --> 100%
Answer:
The answer is (C)
17.37 + .50x
ED2021
the camdens drove 116 miles on 5 gallons of gas. at this rate, how many miles can they drive on 7 gallons of gas
Answer:
162.4 miles
Step-by-step explanation:
We can write a ratio to solve
116 miles x miles
----------------- = ------------
5 gallons 7 gallons
Using cross products
116*7 = 5x
Divide by 5
812 /5 = 5x/5
162.4 =x
162.4 miles
PLEASE HELP THIS IS DUE ASAP!!!!!!!!!!!!!!
the answer is 1/12
the first rolling a 4 has a 1/6 chance of happening and half of the numbers on the die are odd, so 1/6*1/2=1/12
I do not understand this and could use help it needs the work shown
Answer:
a = 9
Step-by-step explanation:
The given trinomial is :
[tex]x^2-6x+\_\_\__[/tex]
let the blank is a.
So, we need to find the value of a so that it results in a perfect square trinomial.
We know that, [tex](m-n)^2=m^2-2mn+n^2[/tex]
So,
[tex]x^2-6x+a=x^2-2(1)(3)+3^2\\=(x-3)^2[/tex]
So, the value of a is 9. If a is 9, then only it would be a perfect square trinomial.
Answer please I’m stuck
Answer:
196
Step-by-step explanation:
We will use the formula:
Surface Area of A / Surface area of B = (Height of A /Height of B)^2
49/S2 = (4/8)^2
49/S2 = 1/4
S2 = 196
Answred by Gauthmath
Help please, thanks as always in advance.
Which correlation coefficient indicates the data set with the strongest linear correlation?
0.41
−0.25
0.66
−0.83
Step-by-step explanation:
Which correlation coefficient indicates the data set with the strongest linear correlation?
0.66
The correlation coefficient indicates the data set with the strongest linear correlation is -0.83
What is correlation coefficient?"It measures the strength of the relationship between two relative variables."
What is linear correlation?"When the rate of change is constant between two variables then it is said to be linear correlation."
For given example,
We have been given correlation coefficients.
We need to find the correlation coefficient that indicates the data set with the strongest linear correlation.
We know, the correlation coefficient lies between -1 to 1.
So, the strongest linear correlation is indicated by a correlation coefficient of -1 or 1.
From given correlation coefficients,
-0.83 is close to -1.
Therefore, the correlation coefficient indicates the data set with the strongest linear correlation is -0.83
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find the missing side of the triangle
Answer:
x = 34
Step-by-step explanation:
Pytago:
x[tex]30^{2} + 16^{2} = x^2\\x = \sqrt{30^2 + 16^2} \\x = 34[/tex]
i keel asking for the dang answer why wont anyone tell me it a store sells pencils pens and markers that sells two times as many markers as pencils and three times as many pens as pencils is the store sells a total of 1950 pencils and pens and markers in a week how many of each were sold
Answer:
Pencils = 325 ; Pens = 975 ; Markers = 650
Step-by-step explanation:
Let :
Number of Pencils = x
Number of pens = y
Number of markers = z
2 times as many markers as pencils
z = 2x
3 times as many pens as pencils
y = 3x
x + y + z = 1950
Write z and y in terms of x in the equation :
x + 3x + 2x = 1950
6x = 1950
Divide both sides by 6
6x / 6 = 1950 / 6
x = 325
Number of pencils = 325
Pens = 3 * 325 = 975
Markers = 2 * 325 = 650
Pencils = 325 ; Pens = 975 ; Markers = 650
