Answer:
a) [tex]t=\frac{18.4-17.5}{\frac{2.2}{\sqrt{45}}}=2.744[/tex]
The degrees of freedom are given by:
[tex]df=n-1=45-1=44[/tex]
The critical value for this case is [tex]t_{\alpha}=1.68[/tex] since the calculated value is higher than the critical we have enough evidence to reject the null hypothesis and we can conclude that the true mean is significantly higher than 18.4
b) [tex]p_v =P(t_{(44)}>2.744)=0.0044[/tex]
Step-by-step explanation:
Information given
[tex]\bar X=18.4[/tex] represent the sample mean
[tex]s=2.2[/tex] represent the sample standard deviation
[tex]n=45[/tex] sample size
[tex]\mu_o =17.5[/tex] represent the value to verify
[tex]\alpha=0.05[/tex] represent the significance level
t would represent the statistic
[tex]p_v[/tex] represent the p value
Part a
We want to test if the true mean is higher than 17.5, the system of hypothesis would be:
Null hypothesis:[tex]\mu \leq 17.5[/tex]
Alternative hypothesis:[tex]\mu > 17.5[/tex]
The statistic is given by:
[tex]t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}[/tex] (1)
And replacing we got:
[tex]t=\frac{18.4-17.5}{\frac{2.2}{\sqrt{45}}}=2.744[/tex]
The degrees of freedom are given by:
[tex]df=n-1=45-1=44[/tex]
The critical value for this case is [tex]t_{\alpha}=1.68[/tex] since the calculated value is higher than the critical we have enough evidence to reject the null hypothesis and we can conclude that the true mean is significantly higher than 18.4
Part b
The p value would be given by:
[tex]p_v =P(t_{(44)}>2.744)=0.0044[/tex]
There are 225 students at March middle school. On Friday, 135 students wore spirit shirts. What percent of the students did Not wear spirit shirts on Friday?
Answer:
40%
Step-by-step explanation:
To find the answer to this, you first can find out what percentage of students did wear spirit shirts. To do this you can divide 135 by 225 to give you 0.6. To convert the decimal into a percentage you can simply multiply by 100, giving you 60%. Then to find the percentage of students that did not wear spirit shirts, you can subtract 60 from 100, giving you 40%.
At a gas station, 50% of the customers use regular gas, 30% use mid-grade gas and 20% use premium gas. Of those customers using regular gas, only 30% fill their tanks. Of those customers using mid-grade gas, 60% fill their tanks, whereas of those using premium, 50% fill their tanks. If the next customer fills the tank, what is the probability that he uses premium gas
Answer:
The probability is 0.2326 or 23.26%.
Step-by-step explanation:
The probability that a random customer fills their tank with premium gas is:
[tex]P( prem\ \&\ fill) = 0.2*0.5=0.10[/tex]
The probability that a random customer fills their tank is given by:
[tex]P(fill)=P( reg\ \&\ fill)+P( mid\ \&\ fill)+P( prem\ \&\ fill)\\P(fill) = 0.5*0.3+0.3*0.6+0.2*0.5\\P(fill) = 0.43[/tex]
Therefore, the probability that a customer used premium gas given that hey have filled their tank is:
[tex]P(prem| fill) = \frac{P( prem\ \&\ fill) }{P(fill)} \\P(prem| fill) =\frac{0.10}{0.43}=0.2326[/tex]
The probability is 0.2326 or 23.26%.
Which set of ordered pairs does NOT represent a function ?
Answer:
The answer is C.
Step-by-step explanation:
For a function, we do a vertical line test. If there is more than one point in one single x-position, it is not a function. Example, the ordered pairs (1, 1) and (1, 2) do NOT describe a function because there are more than one point on x=1.
What is the image of R for a dilation with center (0,0) and a scale factor of 1 1/2?
Answer: The image is (6,-3)
Step-by-step explanation:
The coordinates of R is ( 4,-2) and to find the image using the scale factor 1.5 you will multiply the x coordinates by 1.5 and the y coordinate also by 1.5 to have the new image of R.
4 * 1.5 = 6
-2 * 1.5 = -3
The new coordinates care (6, -3)
Find the area of a triangle bounded by the y-axis, the line f(x)=9−2/3x, and the line perpendicular to f(x) that passes through the origin. Area =
Answer:
The area of the triangle is 18.70 sq.units.
Step-by-step explanation:
It is provided that a triangle is bounded by the y-axis, the line [tex]f(x)=y=9-\frac{2}{3}x[/tex].
The slope of the line is: [tex]m_{1}=-\frac{2}{3}[/tex]
A perpendicular line passes through the origin to the line f (x).
The slope of this perpendicular line is:[tex]m_{2}=-\frac{1}{m_{1}}=\frac{3}{2}[/tex]
The equation of perpendicular line passing through origin is:
[tex]y=\frac{3}{2}x[/tex]
Compute the intersecting point between the lines as follows:
[tex]y=9-\frac{2}{3}x\\\\\frac{3}{2}x=9-\frac{2}{3}x\\\\\frac{3}{2}x+\frac{2}{3}x=9\\\\\frac{13}{6}x=9\\\\x=\frac{54}{13}[/tex]
The value of y is:
[tex]y=\frac{3}{2}x=\frac{3}{2}\times\frac{54}{13}=\frac{81}{13}[/tex]
The intersecting point is [tex](\frac{54}{13},\ \frac{81}{13})[/tex].
The y-intercept of the line f (x) is, 9, i.e. the point is (0, 9).
So, the triangle is bounded by the points:
(0, 0), (0, 9) and [tex](\frac{54}{13},\ \frac{81}{13})[/tex]
Consider the diagram attached.
Compute the area of the triangle as follows:
[tex]\text{Area}=\frac{1}{2}\times 9\times \frac{54}{13}=18.69231\approx 18.70[/tex]
Thus, the area of the triangle is 18.70 sq.units.
Please answer this correctly
4yd^2
2yd^2
6yd^2
Step-by-step explanation:
Rule: height x base/2
The area of the big triangle=2 x 4/2 = 4 yd^2
The area of the small one= 2 x2/2 =2yd^2
The total area of the trapezoid is the sum of these areas= 2+4=6yd^2
What is (-2)+(-5) on a number line explained
Answer:
(-2)+(-5) = -7
Step-by-step explanation:
-2 + -5 = -7
but negative PLUS a negative equals a negative so the answer is going to be a negative, and just to keep in mind in the future that a negative PLUS a negative will give us a negative and negative TIMES a negative gives us a positive, and a positive PLUS a positive gives us a positive and a positive TIMES a positive gives us a positive and Negative times a positive equals a negative and negative PLUS a positive find the sum take the absolute value of each integer and then subtract the values.
The answer is -7 hope this helped! :)
Answer:
-7
Step-by-step explanation:
they add upp because they both negative
someone answer this
Answer:
16
Step-by-step explanation:
The right triangle shown is a 30:60:90 triangle.
30:60:90 right triangles have a 1:sqrt(3):2 ratio between their sides.
Since the side opposite from the 30 degree is 8, and x is opposite from the 90 degree angle, 8 and x have a 1:2 ratio, or 8:16.
3
Type the correct answer in the box. Use numerals instead of words. If necessary, use / for the fraction bar.
The product of (3 + 2) and a complex number is (17 + 71).
The complex number is
Answer:
5-i
Step-by-step explanation:
Product=multiplication
Let the complex number=x
(3+2i)*x=17+7i
x=17+7i / 3+2i
x=(17-7i)*(3-2i)/(3+2i)*(3+2i)
=51-34i+21i+14i^2 / 9+6i+6i+4i^2
=51+13i+14i^2 / 9+12i+4i^2
= (51+14 - 13i) / 13
= (65 -13i) / 13
= 65 / 13 - 13 i / 13
= 5 - i.
Help asap giving branlist!!
Answer:
option 3
Step-by-step explanation:
x = 2 is a vertical line with an x-intercept of (2, 0) so the answer is Option 3.
Answer:
Option 3
Step-by-step explanation:
The value of x will always be 2. Y can be anything it wants to be and x will still be 2 no matter what, You could pick multiple points on the line for each graph, and only Option 3 will have x always being 2.
Which shows one way the equation can be represented in words?
Z-6=1.4
Answer:
6 less than a number is equal to 1 and 4 tenths
Step-by-step explanation:
what is the solution for this equation [3y+7]=13
Answer:2
Step-by-step explanation:
3y+ 7= 13
3y= 13 - 7
3y= 6
Y = 6/3
Y= 2
We are interested in finding an estimator for Var (Xi), and propose to use V=-n (1-Xn). 0/2 puntos (calificable) Now, we are interested in the bias of V. Compute: E [V]-Var (Xi)-[n Using this, find an unbiased estimator V for p (1 - p) if n22. rite barX_n for Л n . 72 1--X 7t
Here is the full question .
We are interested in finding an estimator for [tex]Var (X_i )[/tex] and propose to use :
[tex]\hat {V} = \bar {X}_n (1- \bar {X} )_n[/tex]
Now; we are interested in the basis of [tex]\hat V[/tex]
Compute :
[tex]E \ \ [ \bar V] - Var (X_i) =[/tex]
Using this; find an unbiased estimator [tex][ \bar V][/tex] for [tex]p(1-p) \ if \ n \geq 2[/tex]
Write [tex]bar \ x{_n} \ for \ X_n[/tex]
Answer:
Step-by-step explanation:
[tex]\bar X_n = \dfrac{1}{n} {\sum ^n _ {i=1} } \\ \\ E(X_i) = - \dfrac{1}{n=1} \sum p \dfrac{1}{n}*np = \mathbf{p}[/tex]
[tex]V(\bar X_n) = V ( \dfrac{1}{n_{i=1} } \sum ^n \ X_i )} = \dfrac{1}{n^2} \sum ^n_{i=1} Var (X_i) \\ \\ = \dfrac{1}{n^2} \ \sum ^n _{i=1} p(1-p) \\ \\ = \dfrac{1}{n^2}*np(1-p) \\ \\ = \dfrac{p(1-p)}{n}[/tex]
[tex]E( \bar X^2 _ n) = Var (\bar X_n) + [E(\bar X_n)]^2 \\ \\ = \dfrac{p(1-p)}{n}+ p \\ \\ = p^2 + \dfrac{p(1-p)}{n} \\ \\ \\ \hat V = \bar X_n (1- \bar X_n ) = \bar X_n - \bar X_n ^2 \\ \\ E [ \hat V] = E [ \bar X_n - \bar X_n^2] \\ \\ = E[\bar X_n ] - E [\bar X^2_n] \\ \\ = p-(p^2 + \dfrac{p(1-p)}{n}) \\ \\ = p-p^2 -\dfrac{p(1-p)}{n}[/tex]
[tex]=p(1-p)[1-\dfrac{1}{n}] = p(1-p)\dfrac{n-1}{n}[/tex]
[tex]Bias \ (\bar V ) = E ( \hat V) - Var (X_i) \\ \\ = p(1-p) [1-\dfrac{1}{n}] - p(1-p) \\ \\ - \dfrac{p(1-p)}{n}[/tex]
Thus; we have:
[tex]E [\hat V] = p(1-p ) \dfrac{n-1}{n}[/tex]
[tex]E [\dfrac{n}{n-1} \ \ \bar V] = p(1 -p)[/tex]
[tex]E [\dfrac{n}{n-1} \ \ \bar X_n (1- \bar X_n )] = p (1-p)[/tex]
Therefore;
[tex]\hat V ' = \dfrac{n}{n-1} \bar X_n (1- \bar X_n)[/tex]
[tex]\mathbf{ \hat V ' = \dfrac{n \bar X_n (1- \bar X_n)} {n-1}}[/tex]
Type your answers into the boxes.
There are 36 students in a class. The pie chart shows the colour of their hair.
Students' Hair Colours
40°
Red
Blonde
Dark
240°
How many students have blonde hair?
How many students have dark hair?
How many students have red hair?
Answer:
(a)24
(b)8
(c)4
Step-by-step explanation:
Number of STudents in the Class = 36
Angle representing Students with Red Hair =40 degrees
Angle representing Students with Blonde Hair =240 degrees
Therefore:
(a)Number of Students with Blonde Hair
[tex]=\dfrac{240^\circ}{360^\circ} \times 36\\\\ =24$ students[/tex]
(b)Number of Students with Dark Hair
Angle representing students with dark hair = 360-(240+40)=80 degrees
Therefore:
Number of Students with Dark Hair
[tex]=\dfrac{80^\circ}{360^\circ} \times 36\\\\ =8$ students[/tex]
(c)Number of Students with Blonde Hair
[tex]=\dfrac{40^\circ}{360^\circ} \times 36\\\\ =4$ students[/tex]
There are 8 students that have blond hair
There are 24 students that have dark hair
There are 4 students that have red hair
Please find attached the pie chart used in answering this question
A pie chart is a graph that displays information in a circle. The circle is divided into slices which represent a numerical proportion. The sum of angles in a pie chart is 360 degrees
To determine the number of students with a type of hair, use this formula :
(degree of the slice that represents the hair type / 360) x total number of students in the class
Degree of the slice that represents blond hair = 360 - (240 + 40) = 80
Students that have blonde hair = [tex]\frac{80}{360}[/tex] x 36 = 8
Students that have dark hair = [tex]\frac{240}{360}[/tex] x 36 = 24
Students that have red hair = [tex]\frac{40}{360}[/tex] x 36 = 4
To learn more about pie charts, please check : https://brainly.com/question/11433309?referrer=searchResults
Tom wants new carpeting for his bedroom. His room is a 9 metres by 7 metres rectangle.
How much carpeting does he need to buy to cover his entire bedroom floor
Answer:
63
Step-by-step explanation:
So just find the area of the carpet:
9 * 7 = 63
1. The mean of the data set{9,5,y,2,x} is twice the data set {8,x,4,1,3}. What is (y-x) squared.
2. How many alcohol must be added to480 grams of hand sanitizer that is 24% alcohol to make it a hand sanitizer that is 40% alcohol?
Answer:
1. (y - x)² = 256
2. 128g needed to be added
Step-by-step explanation:
1.
9 + 5 + 2 + y + x = 2(8 + 4 + 1 + 3 + x)
16 + y + x = 32 + 2x
y - x = 16
∴ (y - x)² = 256
2.
x = mass of alcohol to add
480 × 0.24 = 115.2 ← current mass of alcohol
0.4(480 + x) = 115.2 + x (×5)
2(480 + x) = 576 + 5x
960 + 2x = 576 + 5x
3x = 384
x = 128g
I need help with this one
Answer:
-12
Step-by-step explanation:
what is 0.035 as a simplified reduced fraction
Answer:
7/200
Step-by-step explanation:
0.035= 35/1000= 7*5/200*5=7/200
What is the measure of angle L in parallelogrami LMNO?
20°
30°
40°
50°
Answer:
40°
Step-by-step explanation:
2x = 3x - 20 add like terms
x = 20 and angle l is equal to 3x minus 20 so 3 × 20 - 20 = 40°
Submit A political scientist wants to conduct a research study on a president's approval rating. The researcher has obtained data that states that 45% of citizens are in favor of the president. The researcher wants to determine the probability that 6 out of the next 8 individuals in his community are in favor of the president. What is the binomial coefficient of this study? Write the answer as a number, like this: 42.
Answer: 28
Step-by-step explanation: Im taking the same class here is a photo of the work, divide 56/2 than you get 28
Find the distance between the pair of points: (9,−3) and (0,−10).
Answer:
√130 is the distance between (9,-3) (0,-10)
The relationship between the number of pencil sharpener a company can sell each week and the price of each sharpener p is given by the equation x = 2300 − 100 p At what price should the sharpeners be sold if the weekly revenue is to be $ 12000
Answer:
The price p could be any of $8 or $15 .
Step-by-step explanation:
The equation is a relationship between the numbers of pencil sharpener x can sell each week and the price of each sharpener p.
x = 2300 - 100p
xp = 12000
therefore,
x = 12000/p
insert the value of x in the equation
x = 2300 - 100p
12000/p = 2300 - 100p
12000/p + 100p - 2300 = 0
multiply through by p
12000 + 100p² - 2300p = 0
100p² - 2300p + 12000 = 0
divide through by 100
p² - 23 + 120 = 0
Find the number that we can multiply to give 120 and add to give - 23. The number are -15 and - 8.
p² - 8p - 15p + 120 = 0
p(p - 8) - 15(p - 8) = 0
(p - 8)(p - 15)
p = 8 or 15
x = 2300 - 100p
x = 2300 - 100(8)
x = 2300 - 800
x = 1500 pencil sharpener sold
or
x = 2300 - 100(15)
x = 2300 - 1500
x = 800 pencil sharpener sold
The price could be any of $8 or $15 .
Solve for y=x squared -18 solve for x
Step-by-step explanation:
[tex]y = {x}^{2} - 18 \\ y + 18 = {x}^{2} \\ square \: root \: both \: sides \: \\ \sqrt{y + 18} = \sqrt{ {x}^{2} } [/tex]
[tex]x = \sqrt{y + 18} [/tex]
Answer:
√y + 18 = x
Step-by-step explanation:
Let us solve it now.
y = x² - 18
Take -18 to the left side
y + 18 = x²
Now remove the square of x
√y + 18 = x
Find the value of y when equals zero. -7x+3y=30
Answer:
x = -30/7
Step-by-step explanation:
-7x+3y=30
Let y=0
-7x +0 = 30
Divide by -7
-7x /-7 = 30/-7
x = -30/7
Answer:
[tex]-\frac{30}{7}[/tex]
Step-by-step explanation:
y equals zero => y = 0
-7x+3y=30
-7x +3.0 = 30
-7x + 0 = 30
-7x = 30
-7x/-7 = 30/-7
x = -30/7
Hope this helps ^-^
There are 20 pieces of fruit in a bowl and 5 of them are apples. What percent of the fruit are apples?
Step-by-step explanation:
20fruits=100%
5fruits=?
5x100/20 5fruitsx5%
=24%
Antonio burns 75 calories for every 15 minutes
Answer is 5 calories/min
75 divided by 15 is 5
Answer:five cal per min.15 in five groups equals ''75''
Among 21- to 25-year-olds, 29% say they have driven while under the influence of alcohol. Suppose that three 21- to 25-year-olds are selected at random. a)What is the probability that all three have driven while under the influence of alcohol
Answer:
P(3) = 0.0244
P(3) = 2.44%
the probability that all three selected have driven while under the influence of alcohol is 2.44% or 0.0244
Step-by-step explanation:
Given;
The probability that they have driven while under the influence of alcohol is;
P = 29% = 0.29
the probability that all three selected have driven while under the influence of alcohol is;
P(3) = P × P × P
P(3) = 0.29 × 0.29 × 0.29
P(3) = 0.024389
P(3) = 0.0244
P(3) = 2.44%
the probability that all three selected have driven while under the influence of alcohol is 2.44% or 0.0244
Please help! Correct answer only, please! Consider the following table. A movie theatre is planning to increase each of their various ticket prices by $2. Which informational matrix operation below would correctly increase of their prices ticket prices by $2? A. B. C. D.
Answer: D
Step-by-step explanation:
In order to increase each ticket by $2, you are ADDING 2 to each value.
So you create a matrix of all 2's and add that to the given matrix.
[tex]\left[\begin{array}{cc}2&2\\2&2\\2&2\end{array}\right] +\left[\begin{array}{cc}8&10\\12&16\\6&8\end{array}\right]\quad =\quad \large \left[\begin{array}{cc}10&12\\14&18\\8&10\end{array}\right][/tex]
Answer:
Unit 8 test answers
Step-by-step explanation:
1: a.)3x4
2:b.)
3:a.)
4:b.)
5:c.) matrix CD would have the dimensions 7x7
6: a.)
7:67
8:c.)
9:b.) Scott sold 1 van
10:d.)
Solve for n.
11(n – 1) + 35 = 3n
n = –6
n = –3
n = 3
n = 6
Answer:
[tex]n = - 3[/tex]
Second answer is correct
Step-by-step explanation:
[tex]11(n - 1) + 35 = 3n \\ 11n - 11 + 35 = 3n \\ 11n - 3n = 11 - 35 \\ 8n = - 24 \\ \frac{8n}{8} = \frac{ - 24}{8} \\ n = - 3[/tex]
hope this helps
brainliest appreciated
good luck! have a nice day!
If 9: x= x-4, then x=
0 36
18
0 24
6
Answer:
2±√13
Step-by-step explanation:
9/x=x-4
x² -4x - 9=0
x² -4x +4- 13=0
(x -2)²=13
x-2= ±√13
x= 2±√13