Answer:
The correct 90% confidence interval for the difference between women and men in the average number of hours of personal time taken per year is
contained by the interval (0.54 , 5.18)
Step-by-step explanation:
Given that:
for women
sample size = n₁ = 16
sample mean [tex](\bar X_1)[/tex] = 24.75
standard deviation s₁ = 2.84
for men
sample size for men = n₂ = 7
sample mean [tex](\bar X_2)[/tex] = 21.89
standard deviation s₂ = 3.29
degree of freedom = [tex](n_1 + n_2 )-2[/tex]
= 16 + 7 -2
= 21
The critical value for [tex]\alpha = 0.1 \ and \ df \ of \ 21 \ is :[/tex]
[tex]t_{0.005;21}= 1.721[/tex]
The pooled standard deviation can be calculated as follows since the population variances are assumed to be equivalent.
[tex]s_p = \sqrt{\dfrac{(n_1 -1)s_1^2+(n_2-1)s_2^2}{n_1+n_2-2}}[/tex]
[tex]s_p = \sqrt{\dfrac{(16 -1)2.84^2+(7-1)3.29^2}{16+7-2}}[/tex]
[tex]s_p = \sqrt{\dfrac{(15)8.0656+(6)10.8241}{21}}[/tex]
[tex]s_p = 2.976[/tex]
The standard error is estimated as follow:
[tex]se = s_p\sqrt{\dfrac{1}{n_1} + \dfrac{1}{n_2}}[/tex]
[tex]se = 2.976\sqrt{\dfrac{1}{16} + \dfrac{1}{7}}[/tex]
se = 1.348
Finally, the confidence interval [tex]C.I = ( x_1 -x_2 -t_c \times se \ \ ; \ \ x_1-x_2 +t_c \times se)[/tex]
[tex]=(24.75 - 21.89 -1.721 \times 1.348 \ \ , \ \ 2475 - 21.89 + 1.721 \times 1.348) \\ \\ \mathbf{ = (0.54 \ \ , \ \ 5.18)}[/tex]
What is a cubic polynomial function with zeros -20, -15, and -6?
What is a quartic polynomial function with zeros -20, -16, -11, and -9?
What are the zeros of x^3 + 16x^2 + 60x? What are their multiplicities?
Answer:(x + 1)(x - 1)(x + 5)(x - 3) is the fully factored form of the polynomial.
The zeros are (-1, 0), (1, 0), (-5, 0), and (3, 0).
x^4 + 2x^3 - 16x^2 - 2x + 15
We can use the rational roots theorem to find some of the possible roots, and after finding just one root, we can simplify this polynomial.
List factors of 15:
1, 3, 5, 15.
List factors of 1:
1.
Our possible rational factors are:
+/- 1, +/- 3, +/- 5, +/- 15.
To find factors, we can use the remainder theorem.
Replace all x values with 1.
1^4 + 2(1)^3 - 16(1)^2 - 2(1) + 15 = 0
Because the answer is zero, it means that 1 is a root.
We can divide this polynomial by x - 1 to find a simplified form.
After dividing, our quotient is: x^3 + 3x^2 - 13x - 15
We can continue finding factors by using the rational roots theorem. Once we have only three terms, we can try to factor using the AC method.
Our next possible root is -1.
(-1)^3 + 3(-1)^2 - 13(-1) - 15 = 0
We know that -1 is also a root, and so we can divide the polynomial by x + 1.
After diving we're left with x^2 + 2x - 15.
Now, we can try to factor using the AC method.
List factors of -15.
1 * -15
-1 * 15
3 * -5
-3 * 5 (these digits satisfy the criteria.)
Split the middle term.
x^2 - 3x + 5x - 15
Factor binomials.
x(x - 3) + 5(x - 3)
Rearrange binomials.
(x + 5)(x - 3)
Add in the two factors we already factored out.
(x - 1)(x + 1)(x + 5)(x - 3)
Step-by-step explanation:
a chemist is researching different sustainable fuel sources
Answer:
Wind
Hydroelectric Power
Solar
Geothermal
A city councilwoman is concerned that the new contractor she hired is taking too long to replace defective streetlights. She would like to perform a hypothesis test to determine if the replacement time for streetlights under the new contractor is in fact longer than the replacement time under the previous contractor, which was 3.2 days on average. She selects a random sample of 12 streetlight service calls and obtains the following times to replacement (in days). Use a significance level of 0.05
6.2 7.15.4 5.57.52.6 4.3 2.9 3.7 0.7 5.6 1.7
Required:
a. Define μ in the context of the problem and state the appropriate hypotheses.
b. State and check the conditions for a hypothesis test of the mean. Since the sample size is smaller than 30, you will need to calculate a normal probability plot to determine if the data come from a normal distribution.
Answer:
There is significant evidence to conclude that the replacement time for streetlights under the new contractor is longer than the replacement time under the previous contractor.
Step-by-step explanation:
Given the data :
6.2 7.1 5.4 5.5 7.5 2.6 4.3 2.9 3.7 0.7 5.6 1.7
The hypothesis:
H0: μ = 3.2
H1 : μ > 3.2
n = sample size = 12
The sample mean, xbar = ΣX / n
xbar = 53.2 / 12
xbar = 4.43
Using calculator;
Sample standard deviation, s = 2.147
The test statistic :
(xbar - μ) ÷ (s/sqrt(n))
(4.43 - 3.2) ÷ (2.147/sqrt(12)
1.23 / 0.6197855
Test statistic = 1.985
The Pvalue using the Pvalue from Tscore calculator :
Tscore = 1.985 ; df = 12 - 1 = 11
Pvalue = 0.036
Since Pvalue < α ; We reject the Null
Hence, we conclude that the replacement time for streetlights under the new contractor is longer than the replacement time under the previous contractor.
What is the slope of the line represented by the equation y = x-3?
0 -3
5
O
3
Answer:
slope (m) = 4/5
Step-by-step explanation:
Equation of straight line: y = mx + b
∴ 4/5 is the slope
Find the length of the chord made by 3x2 - y2 = 3 and y + x – 5 = 0.
Answer:
The correct answer is "9√2 units".
Step-by-step explanation:
The given equations are:
⇒ [tex]3x^2-y^2=3[/tex]...(equation 1)
⇒ [tex]y+x-5=0[/tex]...(equation 2)
According to the 2nd equation, we get
⇒ [tex]y+x-5=0[/tex]
⇒ [tex]y=5-x[/tex]
On substituting the value of "y" in the 1st equation, we get
⇒ [tex]3x^2-y^2=3[/tex]
[tex]3x^2-(5-x)^2=3[/tex]
[tex]3x^2-(25+x^2-10x)=3[/tex]
[tex]2x^2+10x-28=0[/tex]
On taking common, we get
[tex]x^2+5x-14=0[/tex]
On applying factorization, we get
[tex]x^2+7x-2x-14=0[/tex]
[tex]x(x+7)-2(x+7)=0[/tex]
[tex](x+7)(x-2)=0[/tex]
[tex]x+7=0[/tex]
[tex]x=-7[/tex]
or,
[tex]x-2=0[/tex]
[tex]x=2[/tex]
Now,
The points are:
(-7, 12) = (x₁, y₁)
(2, 3) = (x₂, y₂)
By using the distance formula, the length of chord will be:
= [tex]\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]
On substituting the values in the above formula, we get
= [tex]\sqrt{(2-(-7))^2+(3-12)^2}[/tex]
= [tex]\sqrt{(9)^2+(-9)^2}[/tex]
= [tex]\sqrt{81+81}[/tex]
= [tex]9 \sqrt{2}[/tex] units
PLEASE HELP !! ILL GIVE BRAINLIEST !!
Answer:
∠VWT and ∠UTW
∠STW and ∠XWT
Step-by-step explanation:
PLEASE HELP IMMEDIATELY!!
Answer:
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Step-by-step e.xplanati:kljkjk
Write a number of grams between 10 and 20, and then write an equivalent amount in milligrams.
Answer:
15 grams and 15000 milligrams
Step-by-step explanation:
John took all his money from his savings account. He spent $108 on a radio and 5/9 of what was left on presents for his friends. Of the money remaining, John put 5/6 into a checking account and the last remaining $80 was left to charity. How much money did John originally have in his savings account?
Answer:
I believe its 313$
Step-by-step explanation:
John originally have $1,118 in his savings account.
Here,
We have to find the original savings account of John.
What is Number system?
A system of writing to express numbers is called Number system.
Now,
Let us assume amount of money John originally have in his savings account = $x
Money spent on a radio = $108
Remaining money = x - 108
Money spent on presents for his friends = Two third of remaining money = 5/9 (x - 108).
(Because 1 - 5/9 = 1/1 - 5/9 = 4/9)
Remaining money = 4/9 (x - 108).
Five sixth of his remaining money into a checking account = 5/6 * 4/9(x - 108)
( because 1 - 5/6 = 1/1 -5/6 = 1/6)
Remaining money = 1/6 *4/9 (x - 108).
Final remaining money = 1/6 *4/9 (x - 108)
And that is equal to the money donated to charity.
We can setup an equation now.
1/6 *4/9 (x - 108) = 80
4(x - 108) = 80 * 9 *6
x - 108 = 20 * 54
x = 1080 + 108
x = 1,188
Therefore, John originally have $1,118 in his savings account.
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Solve: 7.2h = 57.6 A. h= 0.8 B. h = 8 C. h = 50.4 D. h = 80
Answer:
B. h=8
Step-by-step explanation:
The answer is B. h=8. I know because I solved to get h by itself. First, I set up the problem.
7.2h=57.6
Then, I divided each side by 7.2, so I could get h by itself.
h=8
You can check to make sure this is correct by plugging in the value we got for h into the equation.
7.2(8)=57.6
In conclusion, the answer is B. h=8
How do I solve 8/x-0.16=0.64
Answer:
yo my bad
x=10 the other person solved it
Answer:
x=10
Step-by-step explanation:
8/x=0.8
8=0.8x
x=10
help please need asap
Answer:
A. Obtuse B. Right C. Acute D. Acute Hope this helps :)
A political pollster wants to know what proportion of voters are planning to vote for the incumbent candidate in
an upcoming election. A poll of 150 randomly selected voters is taken from the more than 2,000 voters in the
population, and 78 of those selected plan to vote for the incumbent candidate.
Based on this sample, which of the following is a 90% confidence interval for the proportion of all voters who
plan to vote for the incumbent candidate?
Answer:
90% confidence interval -> {0.4529, 0.5871}
Step-by-step explanation:
Check conditions for a 1-proportion z-interval:
np>10 -> 150(0.52)>10 -> 78>10 √
n(1-p)>10 -> 150(1-0.52)>10 -> 72>10 √
Random sample √
n>30 √
For a 90% confidence interval, the critical value is z=1.645
The formula for a confidence interval is:
CI = p ± z√[p(1-p)/n]
Given:
p = 78/150 = 0.52
n = 150
z = 1.645
Therefore, the 90% confidence interval is:
CI = 0.52 ± 1.645√[0.52(1-0.52)/150] = {0.4529, 0.5871}
Context: We are 90% confident that the true proportion of all voters who
plan to vote for the incumbent candidate is contained within the interval
The differnce in price in colerd pencils and mechanical pencils is $0.20. If I purchased 18 colord pencils and 22 mechanical pencils for $27.60, what is the cost of the mechical pencil
Answer: Mechanical Pencils are $0.60
Colored Pencils are $0.80
Step-by-step explanation:
18c+22m=27.60
c-m=.20
+m +m
so c= .20+m
Susitituete 18(.20+m)+22m=27.60
3.6+18m +22m=27.60
40m=27.60
40m=24
m=.60
c=.20+(.60)
c=.80
What is the volume, in cubic feet of the tent.
Answer:
96ft³
Step-by-step explanation:
Okay, so the formula for finding the volume of a triangular prism is base x height, so we first have to find the base:
6 x 4 ÷ 2 = 12
So then we plug our numbers into the formula:
12 x 8 = 96
So, the volume of the tent is 96ft³
hope this helps:)
Suppose one serving of vegetables is 3/4 cup. How many servings there in 3 1/2 cups?
Explain your reasoning
Answer:
14/3 or 4.6
Step-by-step explanation:
you would do 3.5 divided by .75 (=^w^=)
Find the area of the semicircle. Round to the nearest hundredth if necessary.
9514 1404 393
Answer:
8π m² ≈ 25.13 m²
Step-by-step explanation:
The formula for the area of a circle is ...
A = πr²
The area of a semicircle is half that. Also, the radius (r) is half the diameter. So. the area of this semicircle is ...
A = (1/2)π(4 m)² = 8π m² ≈ 25.13 m²
__
Comment on pi
If you use the 3-digit value 3.14 for pi to compute this 4-digit result, you will get 25.12.
Given an equilateral triangle with sides of length 9, find the length of the altitude.
NEED ANSWER ASAP WILL GIVE BRAINLIEST FOR CORRECT ANSWER
Answer:
a person jumping on a trampoline
please help im stuck on this
Answer:
[tex]x = 0 \: y = - 2 \: \: \: \: x = 1 \: y = \frac{ - 13}{9} [/tex]
Answer:
X= ( 18/5 , 0)
Y= (0,-2)
Step-by-step explanation:
substitute 0 for y and solve for x
-5x+9(0) = -18
-5X + 0 = -18
-5X= - 18 - 0
-5X = -18
X = - 18/-5
X = 18/5
solve for Y
-5(0) +9y = -18
= 9y = -18
y= -2
Cquation
Question 2 of 5
How many solutions does 6 -3x = 12 - 6x have?
A. Infinitely many solutions
B. Two solutions
C. One solution
D. No solutions
PLEASE HELP ASAP
Find the greatest common factor of these two expressions:
30x^8 w^4 v^3 and 12w^7 v^5
Answer:
[tex]Factor = 6w^4 v^3[/tex]
Step-by-step explanation:
Given
[tex]30x^8 w^4 v^3[/tex] and [tex]12w^7 v^5[/tex]
Required
Determine the common factor.
To do this, we simply factorize each. SO, we have:
[tex](1)\ 30x^8 w^4 v^3=: 2 * 3 * 5 * x^8 * w^4 * v^3[/tex]
[tex](2)\ 12w^7 v^5:=\ 2 * 2 * 3 * w^4*w^3 * v^3 * v^2[/tex]
Check for similar factors.
[tex]Factor = 2 *3 * w^4 * v^3[/tex]
[tex]Factor = 6w^4 v^3[/tex]
The above represents the similar factor
Find the missing angle. Find x
Find the measure of the exterior angle
Answer:
Step-by-step explanation:
The sum of two interior angles in a triangle is equal to the exterior angle that is supplementary to the third interior angle
for first triangle
90 + 53 = u
143 = u
for the other triangle
102 + x = 4x + 6
102 = 4x + 6 - x
102 = 3x + 6 subtract 6 from both sides
96 = 3x divide both sides by 3
32 = x
Solve
k -4 > 3.2
A) k< -12.8
B) K< -0.8
C) k> -12.8
D) k= -12.8
Determine the value of x and name the type of triangle.
8x + 2
70°
60°
The value of x
Type of triangle
8x+2+70°+80° = 180°
8x+132° = 180°
8x = 180°- 132°
x = 48°/8
Hence, x = 6
Interpreting Algebraic Expressions
11+9k=6n
The expressions has 2 terms.
True or false?
The statement is false as the number of terms in the equation is not two
How to determine the number of terms?The equation is given as
11 + 9k = 6n
Consider an equation represented as
a + b = c
The variables a, b and c are the terms of the equation
This means that the equation 11 + 9k = 6n has the following terms
11, 9k and 6n
The number of these terms is 3
So, the equation has three terms
Hence, it is false that the equation has two terms
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Draw a circle whose radius is 3cm?
Answer:
In this problem, first we need to draw a circle of radius 3 cm having a center at point O. Now, take a point P at a distance of 5.5 cm from the center of the circle. Draw a line joining the point O and P. Now draw a perpendicular bisector of the line OP that cuts OP at M.
A party rental company has chairs and tables for rent. The total cost to rent 5 chairs and
3 tables is 31$. The total cost to rent 2 chairs and 6 tables is 52$. What is the cost to rent each chair and each table?
Answer:
1 Chair= $1.25 1 table= $8.25
Step-by-step explanation:
5c+3t=31
2c+6t= 52
-2(5c+3t=31)
-10c-6t=-62
+
2c+6t=52
= -8c=-10
/-8 /-8
c= 1.25 or 1 1/4
2c+6t=52
2(1.25)+6t=52
2.5+6t=52
-2.5 -2.5
6t= 49.5
/6 /6
t= 8 1/4
Jose car rental company charges $2.75 for a pick up plus $1.25 for each mile driven. How much would you pay to travel 25 miles ? How far could you travel for $100 ? Please no link. I can't view them
Answer:
it would be 28.44 sorry if it does not help