Answer:
the answer is 13.6
Step-by-step explanation:
minus 18.78 on both sides
then divide by 2
In a random sample of 42 Democrats from one city, 10 approved of the mayor's performance. In a random sample of 58 Republicans from the city, 12 approved of the mayor's performance. Find a 90% confidence interval for the difference between the proportions of Democrats and Republicans who approve of the mayor's performance.
Answer:
The 90% confidence interval for the difference between the proportions of Democrats and Republicans who approve of the mayor's performance is (-0.1078, 0.1702).
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 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]
Subtraction of normal variables:
When two normal variables are subtracted, the mean is the subtraction of the means while the standard deviation is the square root of the sum of the variances.
In a random sample of 42 Democrats from one city, 10 approved of the mayor's performance.
This means that:
[tex]p_D = \frac{10}{42} = 0.2381, s_D = \sqrt{\frac{0.2381*(1-0.2381)}{42}} = 0.0657[/tex]
In a random sample of 58 Republicans from the city, 12 approved of the mayor's performance.
This means that:
[tex]p_R = \frac{12}{58} = 0.2069, s_R = \sqrt{\frac{0.2069*(1-0.2069)}{58}} = 0.0532[/tex]
Distribution of the difference:
[tex]p = p_D - p_R = 0.2381 - 0.2069 = 0.0312[/tex]
[tex]s = \sqrt{0.0657^2+0.0532^2} = 0.0845[/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 - 0.9}{2} = 0.05[/tex]
Now, we have to find z in the Ztable as such z has a pvalue of [tex]1 - \alpha[/tex].
That is z with a pvalue of [tex]1 - 0.05 = 0.95[/tex], so Z = 1.645.
Now, find the margin of error M as such
[tex]M = zs[/tex]
[tex]M = 1.645*0.0845 = 0.139[/tex]
The lower end of the interval is the sample mean subtracted by M. So it is 0.0312 - 0.139 = -0.1078
The upper end of the interval is the sample mean added to M. So it is 0.0312 + 0.139 = 0.1702
The 90% confidence interval for the difference between the proportions of Democrats and Republicans who approve of the mayor's performance is (-0.1078, 0.1702).
If a trip is 2 1/2 hours in a rain storm but 5/6 of that on a sunny day how long is the trip on a sunny day
what is the x-intercept?
Answer:
-2
Step-by-step explanation:
I'm not 100% sure but...
The x-intercept is when the y is 0.
And if we look at the coordinate plane, then we see that the x-intercept is two units down, and y is zero, which means that it would probably mean that the x-intercept is -2.
A sequence can be generated by using an=12an−1, where n is a whole number greater than or equal to 1.
Given a9=12, what is a10?
5
6
13
24
Answer:
8, 11, 14, 17
Step-by-step explanation:
For example,
Given: an=2an−1−xan=2an−1−x
a5=99a5=99
a3=27a3=27
a5=2a4−x=2(2a3−x)−x=4a3−3x=99a5=2a4−x=2(2a3−x)−x=4a3−3x=99
4(27)−3x=994(27)−3x=993x=108−99=93x=108−99=9
x=3x=3
Which of these nets will not form closed cubes?
Please help me
Answer:
From left to right: 1, 6, and 7
Step-by-step explanation:
Answer:
The first, sixth, and seventh.
Step-by-step explanation:
Referring to the figure, find the value of x
Answer:
x = 18
Step-by-step explanation:
All triangle angles add up to 180 so:
x + 5x + 72 = 180
6x + 72 = 180
6x = 180 - 72
6x = 108
x = 18
Answer:
21.6
Step-by-step explanation:
5x+72=180 (set it to 180 because the total angle sum of a triangle is 180)
5x=108
x=21.6
HELP NOW WHOEVER ANSWERS FIRST WILL GIVE BRAINLYIST
Answer:
c
Step-by-step explanation:
use the pythagorean theorem
Answer:
Its 8
I know this because its bigger than 7 and it cant be 9
What is the answer please help no links I will report
Answer choices
35%
48%
52%
Answer:
Step-by-step explanation:
T-Ball 52% Soccer 48% Basketball 35%
The accompanying table shows the number of bacteria present in a certain culture over a 4 hour period, where x is the time, in hours, and y is the number of bacteria.Write an exponential regression equation for this set of data, rounding all coefficients to the nearest thousandth. Using this equation, determine the number of bacteria present after 11 hours, to the nearest whole number.
Answer:
3r1
The accompanying table shows the number of bacteria present in a certain culture over a 4 hour period, where x is the time, in hours, and y is the number of bacteria.Write an exponential regression equation for this set of data, rounding all coefficients to the nearest thousandth. Using this equation, determine the number of bacteria present after 11 hours, to the nearest whole number.
Answer: 7041 is the answer. I’m not sure how to explain. I took a lucky guess on my quizzez assignment and got it correct.
The ratio 64 to 96 in simplest form is
3
Answer:
nice.
Step-by-step explanation:
14 yd
4. Rondell draws the semicircle shown at the
right. What is the area of the semicircle?
Use 3.14 for T. (Examples 4 and 5)
a line has a slope of 9/5 if one of the points on the line is (-10, -16), which of the following could be another point on the line?
Answer:
(0,2) is the answer - Option C.
Step-by-step explanation:
Equation of a line:
The equation of a line, in point-slope form, is given by:
[tex]y - y_0 = m(x - x_0)[/tex]
In which m is the slope and the point is [tex](x_0,y_0)[/tex]
Slope of 9/5 if one of the points on the line is (-10, -16)
This means that [tex]m = \frac{9}{5}, (x_0,y_0) = (-10,-16)[/tex]. So
[tex]y - y_0 = m(x - x_0)[/tex]
[tex]y - (-16) = \frac{9}{5}(x - (-10))[/tex]
[tex]y + 16 = \frac{9}{5}(x + 10)[/tex]
Which of the following could be another point on the line?
We have to find a point for values of x and y which gives us an identity. So
Option A:
x = -5, y = -6
Lets see
[tex]-6 + 16 = \frac{9}{5}(-5+10)[/tex]
[tex]10 = \frac{9*5}{5}[/tex]
[tex]10 = 9[/tex] -> False
So this is not the answer.
Option B:
x = 4, y = 11
[tex]11 + 16 = \frac{9}{5}(4 + 10)[/tex]
[tex]27 = 9*14/5[/tex]
False
Option C:
x = 0, y = 2
[tex]2 + 16 = \frac{9}{5}(x+10)[/tex]
[tex]\frac{90}{5} = 18[/tex]
[tex]18 = 18[/tex]
True, so (0,2) is the answer - Option C.
What is the median for the set of data shown below 45 23 16 78 24
please please i need help i will mark u brill
Answer:
106 - 8h = 34
Whenever a math question says "when h = 9," they mean you substitute this number where h is in the equation.
106 - 8(9) = 34
106 - 72 = 34
34 = 34
This means the fact that h = 9 is a solution for h.
I hope this helps! I would really appreciate it if you would please mark me brainliest! Have a blessed day!
A chef used 1/4 bag of potatoes to make 1/9 of a gallon
of stew. if he wanted to make a full gallon of stew, how many bags of potatoes would he need?
Answer:
its c
Step-by-step explanation:
What is the area of triangle BCD to the nearest tenth of a square centimeter? Use special right triangles to
help find the height. Show your work.
Answer:
Area = 13.8 cm²
Step-by-step explanation:
Area of a triangle = ½*base*height
base = 4 cm
height = ?
Find height using trigonometry function:
Reference angle = 60°
Opp = height = BC
Adj = 4 cm
Apply TOA:
Tan 60 = Opp/Adj
Tan 60 = BC/4
BC = 4*Tan 60
BC = 6.92820324 ≈ 6.9 cm
✔️Area of triangle = ½*4*6.9
= 13.8 cm²
Please help with this math work!! Solve for x , Assume which appear tangent are tangent
Answer:
photo is not clear so i can't help u
Answer:
i cant really see the q so sorry but goodluck <3
add and write the fraction or mixed number in it's simplest form 2/5+1/4+7/10
Answer:
1 7/20
Step-by-step explanation:
I think that's the answer.
HELP MATH QUESTION!!!!
Answer:
Keep it up
Step-by-step explanation:
Your teacher is nice for posting it to you iif you can not solve again brick it to me and followed me
Consider the functions shown on the graph. A coordinate grid with two lines. One line labeled f(x) and passes through (negative 3, 1), (0, 1), and point (1.5, 1). The second line is labeled g(x) and passes through point (0, negative 1), point (1.5, 1), and point (3, 3). What is the best approximation for the input value when f(x)=g(x)?
Answer:
1.5, C
Step-by-step explanation:
Took the test.
What is the percentage?
Some one please help me ASAP
Answer:
The answer is 4
Step-by-step explanation:
The angles in a triangle add up to 180 degrees.
You have two angles given 90(right angle) and 57.
Add them to get 147 then subtract from 180.
180 - 147 = 33
Set 33 equal to the expression
33 = 4x + 17
33- 17 = 4x
16 = 4x
4 = x
yo im back whats 2+2
Answer:
Its 4
Step-by-step explanation:
[tex]2 + 2 = 4 \\ [/tex]
Answer:
2+2=4 lol
And it says I need 20 characters so here are the 20 characters, bRaInLy
A roller coaster car starts at the loading platform, rises 30.4 meters, and then takes a steep dive of 50.4 meters into a valley. Plot the value of the altitude of the car after taking the steep dive directly on the vertical number line. Assume the platform is at an altitude of O meters. Drawing Tools Click on a tool to begin drawing. Delete Undo Reset
Answer: the answer is 2.5 meters long
Step-by-step explanation:
A researcher believes that there is a difference in how cautious male stray cats and female stray cats are when approaching people. He knows that the stray cat population is 50% male and 50% female. In order to test this hypothesis, he visits 15 different areas where stray cats live and records the gender of the first cat to approach him. He finds that 11 of the 15 cats that approach him are male. Using a sign test and an alpha of .05: A) What is the null hypothesis
Answer:
The null hypothesis is that there is no difference in the mean number of male and female cats
H₀; μ₂ - μ₁ = 0
Step-by-step explanation:
The given parameters are;
The given percentage of male stray cat population = 50%
The given percentage of female stray cat population = 50%
The number of areas the researcher visits, n = 15
The number of stray male cats he finds = 11
The kind of test to be performed = Sign test
The significance level, α = 0.05
A) Therefore the null hypothesis is H₀; μ₂ - μ₁ = 0
The alternative hypothesis is Hₐ; μ₂ - μ₁ ≠ 0.
Simplify: -5 + 3a +
6 - 4a.
Answer:
-a+11
Step-by-step explanation:
hard to explain. but should be correct
Hi I need ur help! (And this is the other one if you saw my last question)
Answer:
Hi gimmie brainly
thanks
solve For X if 9( x²_1 )= 27 x 2187
Answer:
use photomath it'll slove it for you
Step-by-step explanation:
what is the answer to: 12 ≥ 2 (1 + x)
Answer:
6 1/5
Step-by-step explanation:
Answer:
[tex]x\le \:5[/tex]
12≥ 2(1+x)
Switch sides
2(1+x)≤ 12
Divide both sides by 2
2(1+x)2 ≤122
Simplify
1+x≤ 6
Subtract 1 from both sides
1+x−1≤ 6−1
Simplify
[tex]x\le \:5[/tex]
A pencil box is in the shape of a right rectangular prism and filled with unit cubes as shown below. Each unit cube has a length of 1 centimeter (cm). What is the volume of the pencil box?
A - 20 square centimeters
B - 36 cubic centimeters
C - 240 square centimeters
D - 480 cubic centimeters
Answer:480
multiply the L W H