A clinical trial tests a method designed to increase the probability of conceiving a girl. In the study 320 babies were born and 288 of them were girls. Use the sample data to construct a 99% confidence interval estimate of the percentage of girls born. Based on the result, does the method appear to be effective?
Based on the sample data, we can construct a 99% confidence interval estimate for the percentage of girls born as approximately 85.1% to 94.9%.
To construct a confidence interval estimate for the percentage of girls born, we can use the formula for estimating a proportion.
First, we calculate the sample proportion, which is the number of successes (girls) divided by the total number of trials (babies born):
Sample proportion (p-hat) = Number of girls / Total number of babies born
= 288 / 320
= 0.9
Next, we can construct the confidence interval using the sample proportion. Since we want a 99% confidence interval, we need to find the critical value corresponding to that level of confidence. For a two-tailed test, the critical value is obtained from the standard normal distribution (Z-distribution).
Using a Z-table or calculator, the critical value for a 99% confidence level is approximately 2.576.
The margin of error (E) can be calculated as:
Margin of error (E) = Critical value * Standard error
The standard error (SE) for estimating a proportion is given by:
Standard error (SE) = [tex]\sqrt {(p-hat * (1 - p-hat)) / n}[/tex]
where p-hat is the sample proportion and n is the sample size.
Using these values, we can calculate the margin of error:
Standard error (SE) = [tex]\sqrt {(0.9 * (1 - 0.9)) / 320}[/tex]
≈ 0.019
Margin of error (E) = 2.576 * 0.019
≈ 0.049
Finally, we can construct the confidence interval:
Confidence interval = Sample proportion ± Margin of error
= 0.9 ± 0.049
≈ (0.851, 0.949)
Therefore, based on the sample data, we can construct a 99% confidence interval estimate for the percentage of girls born as approximately 85.1% to 94.9%.
Since the interval includes the value of 0.5 (50%), which represents an equal chance of having a girl or a boy, it suggests that the method used in the clinical trial does not significantly increase the probability of conceiving a girl.
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PLEASE HELP! EASY MATH!!
Rosie measures the heights and arm spans of the girls on her basketball team. She plots the data and makes a scatterplot comparing heights and arm spans, in inches. Rosie finds that the trend line that best fits her results has the equation y = x + 2. If a girl on her team is 69 inches tall, what should Rosie expect her arm span to be?
A) 69 = x + 2
x = 67 inches
B) y = 69 - 2 = 67 inches
C) y = 69 inches
D) y = 69 + 2 = 71 inches
Answer:
Your answer would be D. I know this is kind of late, but maybe other people that come up here could get some help
Step-by-step explanation:
Which is the correct stem-and-leaf plot for the data set?
16, 15, 47, 41, 40, 39, 16, 37
Answer:
the first plotting was correct.
Step-by-step explanation:
the values will be arranged in an ascending order from their roots which are the first digit
A new car is purchased for 20300 dollars. The value of the car depreciates at 8.75% per year. What will the value of the car be, to the nearest cent, after 12 years?
My question is more on how do I know how to change the percentage, and what to change it to.
Answer:
Therefore, after 12 years the car will value $6,765.35.
Step-by-step explanation:
okay hi everyone can someone help me with my math reveiw im in 7th grade and i really need help with this and my mom is yelling at me because im failing
During an experiment in which you are investigating the acceleration changes due to force changes, what value must stay constant during these trials?
a. Force
b. Velocity
c. Acceleration
d. Mass
During an experiment of acceleration changes, the value that must stay constant during these trials is d. Mass
Inertia, a basic characteristic of all matter, may be measured quantitatively using mass. When a force is applied, an item effectively provides resistance to changes in velocity or position. The change brought about by an applied force is less the more mass an item has. According to Newton's second law of motion an object's acceleration is inversely proportional to its mass and directly proportional to the net force that has been applied to it. It may be expressed mathematically as F = ma.
The goal of this experiment is to see how variations in force impact acceleration. It is crucial to maintain the mass constant throughout the trials in order to isolate the impact of force on acceleration. Any observable variations in acceleration may be entirely attributable to variations in the applied force by maintaining the mass constant.
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Compare lengths. Select >, <, or = ,
2 km _ 4,000 m
Answer:
2 km < 4,000 m
Step-by-step explanation:
2 km = 2,000 m
Therefore, 2,000 m is less than 4,000 m.
if T= 101+102+103+...+199 find T
...............................................
Sam just purchased a new car. After his employee discount and the sale that the dealership applied to the original
price, Sam paid $13,734.60. If Sam's employee discount was applied to the original price after the dealer discount,
then determine the original price of the vehicle given that the employee discount was 8% and the dealership
discount was 25%. Round your answer to the nearest cent.
a $20,375.21
c. $19,250.13
b. $18,350.33
d. $19,905.22
Answer:
D 19,905
Step-by-step explanation:
19,905.22×25%=4976.31
19905.22-4976.31=14,928.91
14928.91×8%=1194.31
14928.91-1194.31=13734.6
8 divided by 618 ..............
Answer:
0.0129449838188
use a reference angle to write sec290 (where the angle is measured in degrees) in terms of the secant of a positive acute angle. do not include the degree symbol in your answer.
sec 290° = 1/cos 110°= -2.9238.
To find the value of sec 290° using a reference angle, we first need to determine the reference angle for 290°.
The reference angle is the acute angle formed between the terminal side of the given angle (290°) and the x-axis. To find the reference angle, we subtract the nearest multiple of 180° from the given angle:
Reference angle = 290° - 180° = 110°
Now, we can express sec 290° in terms of the secant of the reference angle (110°). The secant function is defined as the reciprocal of the cosine function:
sec(x) = 1/cos(x)
Therefore, sec 290° can be written as:
sec 290° = 1/cos 110° = -2.9238.
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help me please, i’m confused. thanks!
Answer:
Step-by-step explanation:
yo i need help please no links i just need the correct answer to pass this
Given the solid Ethat lies between the cone z2 = x2 + y2 and the sphere x2 + y2 + (z + 2)2 = 2 a) Set up the triple integrals that represents the volume of the solid E in the rectangular coordinate system b)Set up the triple integrals that represents the volume of the solid E in the cylindrical coordinate system c) Evaluate the volume of the solid E
a) The volume of the solid E in rectangular coordinate system is given by: [tex]$$\iiint_{E}[/tex] dx dy dz = [tex]\int_{-2}^{2} \int_{0}^{\sqrt{z^2}} \int_{-\sqrt{z^2 - y^2}}^{\sqrt{z^2 - y^2}} dx dy dz$$[/tex]
b) The volume of the solid E in cylindrical coordinate system is given by: [tex]$$\iiint_{E} \rho d\rho d\theta dz = \int_{0}^{2} \int_{0}^{\frac{\pi}{2}} \int_{0}^{\sqrt{4 - z^2}} \rho d\rho d\theta dz$$[/tex]
c) The volume of the solid E is 11π/3.
a) The solid E that lies between the cone z² = x² + y² and the sphere x² + y² + (z + 2)² = 2.
Volume of solid E in rectangular coordinate systemLet the limits of x, y, z be X, Y, Z respectively.
The limits of X:
From the equation, z² = x² + y²
Z² = X² + Y²
X² = Z² - Y²
Let Z = 0, then X² = - Y² which is impossible. Therefore, Y can take any value such that Y < Z.
The limits of Y:
From the equation, z² = x² + y²
Z² = X² + Y²
Y² = Z² - X²
Let Z = 0, then Y² = - X² which is impossible. Therefore, X can take any value such that X < Z.
Limits of Z:
From the equation x² + y² + (z + 2)² = 2z² + 4z + 8 = 2(Z + 1)² + 6
The limits of z are Z < 2 and Z > - 2.
Volume in rectangular coordinate system:
[tex]$$\iiint_{E}[/tex] dx dy dz = [tex]\int_{-2}^{2} \int_{0}^{\sqrt{z^2}} \int_{-\sqrt{z^2 - y^2}}^{\sqrt{z^2 - y^2}} dx dy dz$$[/tex]
b) Volume of solid E in cylindrical coordinate system
Let the limits of ρ, θ, z be R, Θ, Z respectively.
The limits of R:
From the equation, z² = ρ² cos²θ + ρ² sin²θ
Z² = ρ²
Rho² = Z²/ cos²θ + sin²θ
Rho = Z/ cosθ
Let Z = 0, then Rho = 0. Therefore, R can take any value such that 0 ≤ R < 2.
Limits of Θ:
From the equation, z² = ρ² cos²θ + ρ² sin²θ
Z² = ρ² sin²θ
Theta² = tan⁻²(Z²/ ρ²)
Let Z = 0, then Θ = 0. Therefore, Θ can take any value such that 0 ≤ Θ ≤ π/2.
Limits of Z:
From the equation x² + y² + (z + 2)² = 2z² + 4z + 8 = 2(Z + 1)² + 6
The limits of Z are -2 ≤ Z < 2.
Volume in cylindrical coordinate system:
[tex]$$\iiint_{E} \rho d\rho d\theta dz = \int_{0}^{2} \int_{0}^{\frac{\pi}{2}} \int_{0}^{\sqrt{4 - z^2}} \rho d\rho d\theta dz$$[/tex]
c) Evaluation of the volume of solid E:
Using rectangular coordinate system, the volume of solid E is
[tex]$$\iiint_{E} dx dy dz[/tex] = [tex]\int_{-2}^{2} \int_{0}^{\sqrt{z^2}} \int_{-\sqrt{z^2 - y^2}}^{\sqrt{z^2 - y^2}} dx dy dz$$$$[/tex]
[tex]=\int_{-2}^{2} \int_{0}^{\sqrt{z^2}} [x]_{-\sqrt{z^2 - y^2}}^{\sqrt{z^2 - y^2}} dy dz$$$$=\int_{-2}^{2} \int_{0}^{\sqrt{z^2}} 2\sqrt{z^2 - y^2} dy dz$$$$=\int_{-2}^{2} \left[-\frac{1}{2}(z^2 - y^2)^{3/2}\right]_{y=0}^{y=\sqrt{z^2}} dz$$$$=\int_{-2}^{2} \frac{1}{2}z^3 dz = 0$$[/tex]
Therefore, the volume of solid E using rectangular coordinate system is 0.
Using cylindrical coordinate system, the volume of solid E is
[tex]$$\iiint_{E} \rho d\rho d\theta dz = \int_{0}^{2} \int_{0}^{\frac{\pi}{2}} \int_{0}^{\sqrt{4 - z^2}} \rho d\rho d\theta dz$$$$=\int_{0}^{2} \int_{0}^{\frac{\pi}{2}} \left[\frac{\rho^2}{2}\right]_{0}^{\sqrt{4 - z^2}} d\theta dz$$$$=\int_{0}^{2} \int_{0}^{\frac{\pi}{2}} 2 - \frac{z^2}{2} d\theta dz$$$$=\int_{0}^{2} \left[2\theta - \frac{\theta z^2}{2}\right]_{\theta = 0}^{\theta = \frac{\pi}{2}} dz$$$$=\int_{0}^{2} \pi - \frac{\pi z^2}{4} dz = \frac{11\pi}{3}$$[/tex]
Therefore, the volume of solid E using cylindrical coordinate system is 11π/3.
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A cylindrical test tube holds 6π cm of liquid when filled to the 6cm mark what is the diameter of the test tube to the nearest hundredth of a Centimeter
Answer:
2cm
Step-by-step explanation:
Given data
Capacity/volume of liquid held= 6π cm^3
Height= 6cm
Required
The diameter d of the tube
let us apply the expression for the volume of cylinder
V=πr^2h
6π=πr^2*6
6=r^2*6
r^2= 6/6
r^2=1
r= √1
r=1cm
Hence the diameter d = 2r= 2*1= 2cm
Does the residual plot show that the line of best fit is appropriate for the data?
The correct statement regarding the residual plot in this problem, and whether the line of best fit is a good fit, is given as follows:
Yes, the points have no pattern.
What are residuals?For a data-set, the definition of a residual is that it is the difference of the actual output value by the predicted output value, hence it is defined by the subtraction operation as follows:
Residual = Observed - Predicted.
Hence the graph of the line of best fit should have the smallest possible residual values, and no pattern between the residuals.
As there is no pattern between the residuals in this problem, the line is in fact a good fit and the first option is the correct option.
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Let W = {a + 2x + bx^2 ∈ P2 : a, b ∈ R} with the standard operations in P2. Which of the following statements is true?
A. W is not a subspace of P2 because 0 € W.
The above is true
B. W is a subspace of P2.
The above is true
C. None of the mentioned
D. 1+xEW
A subspace must satisfy three conditions: closure under addition, closure under scalar multiplication, and containing the zero vector. Therefore, the correct statement is B. W is a subspace of P2.
In order to determine whether statement A or B is true, we need to check the subspace criteria.
Let's analyze the statements:
A. W is not a subspace of P2 because 0 € W.
If 0 € W, then W does not contain the zero vector. However, the zero vector is the polynomial 0 + 2(0)x + (0)x^2 = 0, which is an element of W. Thus, statement A is false.
B. W is a subspace of P2.
For W to be a subspace, it needs to satisfy all three subspace criteria. Let's check each criterion:
Closure under addition: Let's take two arbitrary polynomials in W: a + 2x + bx^2 and c + 2x + dx^2. Their sum is (a + c) + 2x + (b + d)x^2, which is also a polynomial in W. Therefore, W is closed under addition.Closure under scalar multiplication: Let's take an arbitrary polynomial in W: a + 2x + bx^2. If we multiply it by a scalar, say k, we get k(a + 2x + bx^2) = ka + 2kx + bkx^2, which is still a polynomial in W. Hence, W is closed under scalar multiplication.Contains the zero vector: The zero vector is the polynomial 0 + 2(0)x + (0)x^2 = 0, which is an element of W. Therefore, W contains the zero vector.Since W satisfies all three subspace criteria, statement B is true.
Therefore, the correct statement is B. W is a subspace of P2.
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What percent of a day does this child spend doing homework? (Round to the nearest whole percent)
Answer:
Step-by-step explanation:
Look at the graph, look at homework and then look at the number right outside of it.
You may need to use the appropriate appendix table to answer this question.
Automobile repair costs continue to rise with the average cost now at $367 per repakt Assume that the cost for an automobile repair is normally distributed with a standard deviation of $88. Answer the following questions about the cost of automobile repairs
(a) What is the probability that the cost will be more than $480 (Round your answer to four decimal places.________
(b) What is the probability that the cost will be less than $240 (Roxind your answer to four decimal places.)________
(c) What is the probability that the cast will be between $240 and $480 (Round your answer to four decimal places.)________
(d) of the cost for your car repair is in the lower 5% of automoble repair charges, what is your matmum possible cast in dollars? (Round your answer to the nearest cent)
$________
The maximum possible cost in dollars is $226.76 (approx).
Standard deviation = $88
Let X be the cost of the automobile repair, then X ~ N(367, 88^2) (normal distribution)
Now, we need to find the following probabilities:
(a) P(X > 480)(b) P(X < 240)(c) P(240 < X < 480)(d)
Find X such that P(X < X1) = 0.05, where X1 is the lower 5% point of X(a) P(X > 480)
We need to find P(X > 480)P(X > 480) = P(Z > (480 - 367)/88) [Standardizing the random variable X]P(X > 480) = P(Z > 1.2955)
Using the standard normal table, the value of P(Z > 1.2955) = 0.0983 (approx)
Hence, the required probability is 0.0983 (approx)(b) P(X < 240)
We need to find P(X < 240)P(X < 240) = P(Z < (240 - 367)/88) [Standardizing the random variable X]P(X < 240) = P(Z < -1.4432)
Using the standard normal table, the value of P(Z < -1.4432) = 0.0749 (approx)
Hence, the required probability is 0.0749 (approx)(c) P(240 < X < 480)
We need to find P(240 < X < 480)P(240 < X < 480) = P(Z < (480 - 367)/88) - P(Z < (240 - 367)/88) [Standardizing the random variable X]P(240 < X < 480) = P(Z < 1.2955) - P(Z < -1.4432)
Using the standard normal table, the value of P(Z < 1.2955) = 0.9017 (approx)and the value of P(Z < -1.4432) = 0.0749 (approx)
Hence, the required probability is 0.9017 - 0.0749 = 0.8268 (approx)(d)
Find the maximum possible cost in dollars, if the cost for your car repair is in the lower 5% of automobile repair charges.
This is nothing but finding the lower 5% point of X.We need to find X1 such that P(X < X1) = 0.05.P(X < X1) = P(Z < (X1 - 367)/88) [Standardizing the random variable X]0.05 = P(Z < (X1 - 367)/88)
Using the standard normal table, the value of Z such that P(Z < Z0) = 0.05 is -1.645 (approx)
Hence, we get,-1.645 = (X1 - 367)/88
Solving for X1, we get: X1 = 88*(-1.645) + 367 = $226.76 (approx)
Therefore, the maximum possible cost in dollars is $226.76 (approx).
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Delano downloaded 9 songs on Saturday and 5 songs on Sunday. How many total songs did he download on Saturday and Sunday?
Answer:
the answer is 14 I pinkie promise!
help me please :)
thank you :P
Answer: Should be 7
Step-by-step explanation:
14/2 is 7
1. What is ✓ 48 in simplified radical form?
Answer:
4[tex]\sqrt{3}[/tex]
Step-by-step explanation:
Using the rule of radicals
[tex]\sqrt{a}[/tex] × [tex]\sqrt{b}[/tex] ⇔ [tex]\sqrt{ab}[/tex] , then
[tex]\sqrt{48}[/tex]
= [tex]\sqrt{16(3)}[/tex]
= [tex]\sqrt{16}[/tex] × [tex]\sqrt{3}[/tex]
= 4[tex]\sqrt{3}[/tex]
A math teacher is trying to analyze her test grades. She surveys the students to find out how many minutes they studied. She then makes a scatterplot of time studying and test grades.
What is the domain?
A) the students' grades on their tests
B) the number of students in the class
C) the different courses the teacher teaches
D) the number of minutes the students studied
In the context of analyzing the relationship between studying time and test grades, the domain of the scatterplot would be the number of minutes the students studied (option D).
The domain refers to the set of possible inputs or variables in a given context. In this case, the scatterplot is being created based on the relationship between the time students spent studying and their corresponding test grades. Therefore, the domain in this context would be the number of minutes the students studied (option D).
The domain represents the independent variable, which is the variable that is controlled or manipulated in the analysis. In this scenario, the math teacher wants to analyze the relationship between studying time and test grades, so the number of minutes studied would be the independent variable. The teacher surveys the students to collect data on the time spent studying, and this variable becomes the domain of the scatterplot.
The range, on the other hand, represents the dependent variable, which is the variable that is measured or observed as an outcome or response. In this case, the dependent variable would be the students' test grades. The scatterplot will show how the test grades correspond to the amount of time students studied.
To summarize, in the context of analyzing the relationship between studying time and test grades, the domain of the scatterplot would be the number of minutes the students studied (option D).
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Marissa has a yard service to help people in her neighborhood. She earns $15 for each lawn she mows, $10 for each yard she weeds, and $5 for each yard she rakes. This month Marissa spent $3 on flyers to send out to neighbors, she purchased a new blower for $26, and paid her brother $18 for helping her mow lawns. If Marissa mowed 4 lawns and raked 8 yards, how much money did she make in profit? 1. 53 2. 100 3. 36 4. 71
Answer:
100-47=53 so 53$ profit
Step-by-step explanation:
ALGEBRAICALLY solve the following system of equations:
y= 22 - 4x + 6 and y=x + 2
Rewrite the expression in the form 3^n
Answer:
n=2
Step-by-step explanation:
[tex]\frac{3.3.3.3.3.3}{3.3.3.3} = 3^{n}[/tex]
[tex]3^{2}[/tex]= [tex]3^{n}[/tex]
n=2
Answer:
[tex]3^1[/tex]
Step-by-step explanation:
[tex]\frac{3*3*3*3*3}{3*3*3*3} =3^1[/tex]
factor this trinomial in standard form 2n^2 + 7n + 5
Answer:
Observation : No two such factors can be found !! Conclusion : Trinomial can not be factored. Equation at the end of step 2 : 2n2 - 7n - 5 = 0. Step 3 : Parabola ...
Step-by-step explanation:
PLEASEEEE HELP ‼️‼️1️⃣
Answer:
8/7
Step-by-step explanation:
12*2=24.
7*3=21
24/21 is divisible by 3
=8/7
Best disc and answer will get BRAINLIEST
Answer:
A is the answer
Step-by-step explanation:
All you have to do is follow the order pair such as 2, 100 and see if that is a correct pair.
Hope that helps
Answer: A. (2, 100)
Step-by-step explanation:
Can anyone help me with this? Please and thank you!
Answer:
x=-6, y=-7
Step-by-step explanation:
Answer:
x = -6, y = -7
Step-by-step explanation:
One way to solve for x and y is using the substitution method
(1) 3x + 4y = -46
(2) 6x + y = -43
Solve for y in equation (2)
6x + y =-43, so y = -43 - 6x
Substitute y = -43 -6x into equation (1)
3x + 4(-43 -6x) = -46
3x -172 -24x = -46
-21x -172 = -46
-21x = 126
x = -6
Find y by substituting x = -6 into equation (2)
6(-6) + y = -43
-36 + y = -43
y = -7