Answer:
Step-by-step explanation:
a. What test is appropriate for this analysis?
A Chi-square test of independence is appropriate for this analysis because it is used to compare two variables or testing relationship on categorical variables.
b. State the null hypothesis:
The null hypothesis is the default hypothesis
[tex]\mathtt{H_o:}[/tex] There is no particular preference for any brand of toothpaste among students.
c. State the alternative hypothesis:
The alternative hypothesis is the research hypothesis which comes in place to challenge the validity of the null hypothesis.
[tex]\mathtt{H_a:}[/tex] There is particular preference for brands of toothpaste among students.
d. Find the critical value:
degree of freedom = n-1
degree of freedom = 3 - 1
degree of freedom = 2
At the level of significance ∝ = 0.05
The confidence interval = 0.95 and degree of freedom = 2, the critical value from the chi-square distribution table = 5.991
e. Calculate the test statistic:
Using the chi square test statistics; we have the following:
Crest Colgate Aquafresh Total
24 13 8 45
Since we have three brands. Then, for each brand, the expected value
= Total /3
= 45/3
=15
Thus:
Chi -square [tex]\mathtt{X^2 = \dfrac{(observed \ value - expected \ value)^2}{expected \ value}}[/tex]
[tex]\mathtt{X^2 = \dfrac{(24 - 15)^2}{15} + \dfrac{(13 - 15)^2}{15} + \dfrac{(8 - 15)^2}{15} }[/tex]
[tex]\mathtt{X^2 = \dfrac{81}{15} + \dfrac{4}{15} + \dfrac{49}{15} }[/tex]
[tex]\mathtt{X^2 = \dfrac{81+4+49}{15}}[/tex]
[tex]\mathtt{X^2 = \dfrac{134}{15}}[/tex]
[tex]\mathtt{X^2 =8.93 }[/tex]
f. Make a decision:
Since the chi-square value is greater than the critical value , we reject the null hypothesis and conclude that the students have particular preference for brands of toothpaste.
Weekly wages at a certain factory are
normally distributed with a mean of
$400 and a standard deviation of $50.
Find the probability that a worker
selected at random makes between
$450 and $500.
Answer:
13.59%
Step-by-step explanation:
Calculate the z-scores.
z = (x − μ) / σ
z₁ = (450 − 400) / 50
z₁ = 1
z₂ = (500 − 400) / 50
z₂ = 2
Use a chart or calculator to find the probability.
P(1 < Z < 2)
= P(Z < 2) − P(Z < 1)
= 0.9772 − 0.8413
= 0.1359
Answer:
13.5
Step-by-step explanation:
Acellus sux
Write the equation of the line that passes through (-1,5) and has a slope of 3 in point slope form
Answer:
y-5=3(x+1)
Step-by-step explanation:
we use the point-slope formula to plug all of our values in.
[tex]y-y_{1}=m(x-x_{1})[/tex]
use the product of powers property to simplify the numeric expression.
4 1/3 • 4 1/5 = _____
Answer:
The value of [tex]4^{\dfrac{1}{3}} {\cdot} 4^{\dfrac{1}{5}[/tex] is [tex]4^{\dfrac{8}{15}}[/tex] .
Step-by-step explanation:
We need to simplify the numeric expression using property. The expression is as follows :
[tex]4^{\dfrac{1}{3}} {\cdot} 4^{\dfrac{1}{5}[/tex]
The property to be used is : [tex]x^a{\cdot} x^b=x^{a+b}[/tex]
This property is valid if the base is same. Here, base is x.
In this given problem, x = 4, a = 1/3 and b = 1/5
So,
[tex]4^{\dfrac{1}{3}} {\cdot} 4^{\dfrac{1}{5}}=4^{\dfrac{1}{3}+\dfrac{1}{5}}\\\\=4^{\dfrac{5+3}{15}}\\\\=4^{\dfrac{8}{15}}[/tex]
So, the value of [tex]4^{\dfrac{1}{3}} {\cdot} 4^{\dfrac{1}{5}[/tex] is [tex]4^{\dfrac{8}{15}}[/tex] .
cherry pies ratio is 240 to 3 pies.how many Cherry's to make 9 pies
Answer:
720
Step-by-step explanation:
It takes 240 cherries to make 3 pies.
9 pies are 3 times 3 pies, so it takes 3 times as many cherries.
3 * 240 cherries = 720 cherries.
[tex]\text{Find how many cherries is needed for 9 pies}\\\\\text{We know that there are 240 total cherries on 3 pies}\\\\\text{Now we need to find how many cherries will 9 pies need}\\\\\text{We simply have to multiply 240 by 3, since 3 multiplied by 3 is 9 pies}\\\text{So we would do the same with the cherries by multiplying it by 3}\\\\240\cdot3=720\\\\\boxed{\text{720 cherries}}[/tex]
An ESP experiment used the "Ten Choice Trainer." This is like the Aquarius, but with 10 targets instead of 4. Suppose that in 1,000 trials, a subject scores 173 correct guesses.
Required:
a. Set up the null hypothesis as a box model.
b. The SD of the box is:_______
c. Make the z-test.
d. What do you conclude?
Answer:
a. The H0 is number of correct guesses is 173
b. Standard Deviation of box is 0.3
c. z-test value is 7.70
d. The difference does not appear due to chances of Variation.
Step-by-step explanation:
The standard deviation is :
[tex]\sqrt{0.1 * 0.9}[/tex] = 0.3
The standard deviation of the box is 0.3 approximately.
Z-score is [tex]\frac{x-u}{standard error}[/tex]
Z-score = [tex]\frac{173-100}{9.4868}[/tex]
the value of z-score is 7.70.
Problem 1. (1 point) A steel ball weighing 128 pounds is suspended from a spring. This stretches the spring 128101 feet. The ball is started in motion from the equilibrium position with a downward velocity of 2 feet per second. The air resistance (in pounds) of the moving ball numerically equals 4 times its velocity (in feet per second) . Suppose that after t seconds the ball is y feet below its rest position. Find y in terms of t. (Note that this means that the positive direction for y is down.)
Answer:
seeed
Step-by-step] explanation:
ddd~!`
You are a great student so you know that you answer probability questions correctly with probability 0.8. A friend told you that "NA" is a correct answer with probability 0.01 in general. Let XX be a random variable that takes on the value 1 if you answer a probability question correctly and 0 otherwise, and let YY be a random variable with takes on the value 1 if "NA" is the correct answer to the probability question and 0 otherwise.Required:a. P [X=0]=_______b. P[Y=1]=________
Answer:
sorry gave wrong answer
Step-by-step explanation:
To the nearest tenth, what is the area of the figure shown in the image? Segment BF is a line of symmetry of the pentagon ABCDE. Use 3.14 for pi. A. 30.3 in.^2 B. 33.0 in.^2 C. 39.3 in.^2 D. 48.3 in.^2 Please include ALL work! <3
Answer:
C, 39.3 in²
Step-by-step explanation:
Lets first find the area of the rectangle part of the house.
To find the area of a rectangle its base × height.
So its 6×4=24 in².
Now lets find the area of the top triangle.
Area for a triangle is (base × height)/2.
The height is 3 inches, because its 7-4. While the base is 6 inches.
(6×3)/2=9 in².
To find the area of the half circle the formula, (piR²)/2.
The radius of the circle is 2 because its half of the diamter which is 4.
(pi2²)/2=6.283 in².
Now we just need to add up the area of every part,
24+9+6.283=39.283in²
estimate the number 4576
Nearest 1000: 5000
Nearest 100: 4600
Nearest 10: 4580
Hope that helped!!! k
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An IQ test is designed so that the mean is 100 and the standard deviation is for the population of normal adults. Find the sample size necessary to estimate the mean IQ score of statistics students such that it can be said with % confidence that the sample mean is within IQ points of the true mean. Assume that and determine the required sample size.
Complete Question
An IQ test is designed so that the mean is 100 and the standard deviation is 24 for the population of normal adults. Find the sample size necessary to estimate the mean IQ score of statistics students such that it can be said with 95% confidence that the simple mean is with in 3 IQ points of the true mean. Assume that standard deviation = 24 and determine the required sample size using technology. Determine if this is a reasonable sample size for a real world calculation.
The required sample size ______ (round up to the nearest integer.
Answer:
The sample size is [tex]n = 246[/tex]
Step-by-step explanation:
From the question we are told that
The mean is [tex]\mu = 100[/tex]
The standard deviation is [tex]\sigma = 24[/tex]
The margin of error is [tex]E = 3[/tex]
Given that the confidence level is 95% then the level of significance is mathematically evaluated as
[tex]\alpha = 100 - 95[/tex]
[tex]\alpha = 5\%[/tex]
=> [tex]\alpha = 0.05[/tex]
Next we obtain the critical value of [tex]\frac{ \alpha }{2}[/tex] from the normal distribution table the value is
[tex]Z_{\frac{\alpha }{2} } = 1.96[/tex]
The sample size is evaluated as
[tex]n = [ \frac{ Z_{\frac{\alpha }{2} } * \sigma }{E }]^2[/tex]
=> [tex]n = [ \frac{ 1.96 * 24 }{3 }]^2[/tex]
=> [tex]n = 246[/tex]
to check if this n is applicable in real world then we calculate E and compare it with the given E
Name the vertex ot XYZ.
Answer:
Line BStep-by-step explanation:
When naming lines, you can use the label of the line, in this case, m, and can also name the points in either direction, since the line goes on forever in both directions (it's different with rays). The leaves only line B as an answer.
The vertex of XYZ would be Y, since the vertex is always the middle number.
I'm always happy to help :)A study claimed residents in a suburb town spend at most 1.9 hours per weekday commuting to and from their jobs. A researcher believed commute times were now different and wants to test this claim by sampling 14 adults. Sample statistics for these 14 adults are: X = 2.2 $=0.7 Can the researcher support the claim that mean commuting time is more than 1.9 hours ? Test using a =.01.
Answer:
There is no sufficient evidence to support the claim that mean commuting time is more than 1.9 hours
Step-by-step explanation:
From the question we are told that
The population mean is [tex]\mu = 1.9 \ hr[/tex]
The sample mean is [tex]\= x = 2.2[/tex]
The standard deviation is [tex]\sigma = 0.7[/tex]
The sample size is [tex]n = 14[/tex]
The level of significance is [tex]\alpha = 0.01[/tex]
The null hypothesis is [tex]H_o : \mu = 1.9 \ hr[/tex]
The alternative hypothesis is [tex]H_a : \mu > 1.9 \ hr[/tex]
Generally the test statistics is mathematically represented as
[tex]t = \frac{\= x - \mu }{ \frac{\sigma}{ \sqrt{n} } }[/tex]
[tex]t = \frac{ 2.2 - 1.9 }{ \frac{0.7 }{ \sqrt{14} } }[/tex]
[tex]t = 1.6036[/tex]
The p-value is obtained from the z-table, the value is
[tex]p-value = P(t > 1.6036) = 0.054401[/tex]
Looking at the value of [tex]p-value \ and \ \alpha[/tex] we see that [tex]p-value > \alpha[/tex]
So we fail reject the null hypothesis
Hence we can conclude that there is no sufficient evidence to support the claim that mean commuting time is more than 1.9 hours
I need help will rate you branliest
Answer:
[tex] {x}^{2} + 5x + 10[/tex]
Answer:
[tex]\large \boxed{x^2 +5x+10}[/tex]
Step-by-step explanation:
A polynomial is an expression that has variables, coefficients, and constants.
An example of a polynomial can be x² - 6x + 2.
To apply Central Limit Theorem on sample proportions in One Sample Proportion test, the sample size and the population proportion under null hypothesis need to satisfy certain conditions. Which of the following scenarios meet the requirement?
A. The sample size is 50 and the population proportion under null hypothesis is 25%.
B. The sample size is 70 and the population proportion under null hypothesis is 90%.
C. The sample size is 50 and the population proportion under null hypothesis is 15%.
D. The sample size is 200 and the population proportion under null hypothesis is 4%.
Answer:
The sample size is 50 and population proportion under null hypothesis is 25% ( A ) meets the requirement
Step-by-step explanation:
when applying the central limit theorem on sample proportions in one sample proportion test .The conditions needed to be satisfied are np > 10, and n( 1-p ) > 10
A) sample size ( n ) = 50
population proportion = 25%
np = 50 * 0.25 = 12.5 which is > 10 ( 1st condition met )
n( 1 - p ) = 50( 1 - 0.25 ) = 37.5 which is > 10 ( second condition met )
B ) sample size (n) = 70
population proportion = 90%
np = 70*0.9 = 63 which is > 10 ( 1st condition met )
n(1-p) = 70 ( 1 - 0.9 ) = 7 which is < 10 ( second condition not met )
C) sample size ( n ) = 50
population proportion = 15% = 0.15
np = 50 * 0.15 = 7.5 which is < 10 ( 1st condition not met )
n ( 1 - p ) = 50 ( 1 - 0.15 ) = 50 * 0.85 = 42.5 which is > 10 ( second condition met )
D) sample size ( n ) = 200
population proportion = 4% = 0.04
np = 200 * 0.04 = 8 which is < 10 ( 1st condition not met )
n ( 1 - p ) = 200 ( 1 - 0.04 ) = 192 which is > 10 ( second condition met )
hence : The sample size of 50 with population proportion under null hypothesis of 25% meets the requirement
A sequence of 1 million iid symbols(+1 and +2), Xi, are transmitted through a channel and summed to produce a new random variable W. Assume that the probability of transmitting a +1 is 0.4. Show your work
a) Determine the expected value for W
b) Determine the variance of W
Answer:
E(w) = 1600000
v(w) = 240000
Step-by-step explanation:
given data
sequence = 1 million iid (+1 and +2)
probability of transmitting a +1 = 0.4
solution
sequence will be here as
P{Xi = k } = 0.4 for k = +1
0.6 for k = +2
and define is
x1 + x2 + ................ + X1000000
so for expected value for W
E(w) = E( x1 + x2 + ................ + X1000000 ) ......................1
as per the linear probability of expectation
E(w) = 1000000 ( 0.4 × 1 + 0.6 × 2)
E(w) = 1600000
and
for variance of W
v(w) = V ( x1 + x2 + ................ + X1000000 ) ..........................2
v(w) = V x1 + V x2 + ................ + V X1000000
here also same as that xi are i.e d so cov(xi, xj ) = 0 and i ≠ j
so
v(w) = 1000000 ( v(x) )
v(w) = 1000000 ( 0.24)
v(w) = 240000
A shopping centre wants to examine the amount of space required for parking. Studies indicated that 50% of staff and shoppers use public transportation. A survey of 1002 was taken, and 483 responded that they used public transportation. At 5% level of significance, is it reasonable to conclude that the survey results indicate a change?
Answer:
We accept H₀ data from the survey is not enough to claim that 50% of the proportion indicated in previous studies have change
Step-by-step explanation:
To get conclusions about the survey we need to develop a hypothesis test of proportion
According to previous studies, (p₀ ) 50 % of staff and customers use public transportation, and we got from a survey 0f 1002 people 483 responded they also use then p = 483/1002 then
n sample size is 1002 and p = 0,482 (48,2 % )
Test Hypothesis
Null hypothesis H₀ p = p₀
Alternative hypothesis Hₐ p < p₀
CI = 95 % α = 5 % α = 0,05 and from z-table we find z score for that value z(c) = - 1,64
z(s) = ( p - p₀ ) / √ (p₀*q₀)/ n p₀ = q₀ = 0,5
z(s) = - 0,018* 31,65 / 0,5
z(s) = - 1,1394
To compare
z(s) and z(c) -1,1394 > 1,64
Then z(s) is inside the acceptance region. We accept H₀ , because we don´t have enough evidence to claim that the survey results indicate a change in
the original proportion
Which of the following is not a characteristic of the F distribution? Multiple Choice It is always right-skewed. It describes the ratio of two variances. It is a family based on two sets of degrees of freedom. It is negative when s12 is smaller than s22.
Answer:
It is negative when s12 is smaller than s22.
Step-by-step explanation:
The F distribution has the following properties.
1) It is always right-skewed. but as the degrees of freedom v1 and v2 become large F distribution approaches normal distribution.
2) It describes the ratio of two variances.
3) It is a family based on two sets of degrees of freedom.
4) It is negative when s12 is smaller than s22. This is not true sometimes as the F distribution does not depend on the population variance but on the two parameters v1 and v2.
Use the Midpoint Rule with n = 10 to approximate the length of c(t) = (5 + sin(4t), 6 + sin(7t)) for 0 ≤ t ≤ 2π. (Round your answer to two decimal places.)
Answer:
34.43
Step-by-step explanation:
A differential of length in terms of t will be ...
dL(t) = √(x'(t)^2 +y'(t)^2)
where ...
x'(t) = 4cos(4t)
y'(t) = 7cos(7t)
The length of c(t) will be the integral of this differential on the interval [0, 2π].
Dividing that interval into 10 equal pieces means each one has a width of (2π)/10 = π/5. The midpoint of pieces numbered 1 to 10 will be ...
(π/5)(n -1/2), so the area of the piece will be ...
sub-interval area ≈ (π/5)·dL((π/5)(n -1/2))
It is convenient to let a spreadsheet or graphing calculator do the function evaluation and summing of areas.
__
The attachment shows the curve c(t) whose length we are estimating (red), and the differential length function (blue) we are integrating. We use the function p(n) to compute the midpoint of the sub-interval. The sum of sub-interval areas is shown as 34.43.
The length of the curve is estimated to be 34.43.
Paisley is playing with a yo-yo. The following graph traces the path of the yo-yo while it is in the air, where y is the height of the yo-yo above the
ground, and x is the time, in seconds, from when the yo-yo leaves Paisley's hand Five stages of the yo-yo's path are marked on the graph.
Which of the five stages shows the slowest rate of change in the yo-yo's height above the ground?
А
В
C
D
Answer:
C
Step-by-step explanation:
From the graph we can notice that the yo-yo crosses five positions: A,B,C,D and E.
The path created by the yo-yo has a parabolic form.
● In the area C, the yoyo crosses the vertex in wich the rate of change equals 0.
●In A the parabola decreases dramatically
● In B, the parabola is decreasing but slower than A.
● In D, the parabola is increasing in a fast way
● In E, the parabola is increasing faster than D.
● In the first half of C, the parabola is decreasing slower than B and A.
● At the vertex, the parabola has a null rate of change.
● In the second half of C, the parabola is increasing but slower than D and E.
So we deduce that C has the slowest rate of change.
Answer:
The answer is C i took the test
Step-by-step explanation:
True or false? "In any sample data set, the sum of all the values is equal to the product of the mean and the sample size."
Answer:
TRUEStep-by-step explanation:
One of the method of analysing the distribution of a dataset is by finding the mean of the dataset which is part of the measure of central of tendency.
Mean of a dataset is also known as the average and it is the ratio of the sum of the individual dataset to the sample size.
Mathematically xbar = ΣXi/N where
ΣXi is the sum of the individual dataset
N is the sample size
xbar is the mean
From the formula, ΣXi = xbar * N
This means that the sum of the individual dataset (all values in the dataset) is equal to the product of the mean (xbar) and the sample size(N).
Hence the statement that In any sample data set, the sum of all the values is equal to the product of the mean and the sample size."is TRUE
Do numbers below 0 make sense outside of the context of temperature? If you think so, give some examples to show how they make sense. If you don’t think so, give some examples to show otherwise.
Answer:
Yes, they make sense outside the context of temperature.
Step-by-step explanation:
If you are standing in a line, and mark your current position as 0 then if you take two steps ahead it can be counted as positive and if you take two steps back from your current position it can be counted as negative. The positive and negative can denote your forward and backward movement respectively.
If we denote the growth in companies revenue as positive and dip as negative then it would also make sense. A positive number would mean profit for the company while a negative sign would show loss.
y =
1
8
x + 3
A) Slope: 8; y-intercept: 3
B) Slope: 1
3
; y-intercept: 1
8
C) Slope: 1; y-intercept: 1
8
D) Slope: 1
8
; y-intercept: 3
Answer:
The slope is 1/8 and the y intercept is 3
Step-by-step explanation:
y = 1/8 x +3
This is in slope intercept form
y = mx+b where m is the slope and b is the y intercept
The slope is 1/8 and the y intercept is 3
What is the rate of change from x = 0 to x = pi over 2 ? (6 points) trig graph with points at: (0, negative 4) and (pi over 2, 0) and (pi, 4) and (3 pi over 2, 0) and (2 pi, negative 4)
Answer:
Rate of Change : 8 / π
Step-by-step explanation:
To determine this rate of change, we have to first consider the points at x = 0 and x = π / 2.
When x = 0, f( x ) = - 4,
When x = π / 2, f( x ) = 0
Remember that rate of change is represented by a change in y / change in x. Therefore,
( 0 - ( - 4 ) ) / ( π / 2 - 0 ),
( 0 + 4 ) / ( π / 2 ),
4 / π / 2 = 8 / π
Therefore the rate of change from x = 0 ➡ x = π / 2 will be 8 / π.
Find an exact value of sin(17pi/12)
●✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎❀✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎●
Hi my lil bunny!
❧⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯☙
[tex]\frac{(17)(3.141593)}{12}[/tex]
= [tex]\frac{53.407075}{12}[/tex]
= [tex]4.45059[/tex]
❧⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯☙
●✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎❀✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎●
If this helped you, could you maybe give brainliest..?
Also Have a great day/night!
❀*May*❀
I have an answer and explanation but I can't type so search up the question you asked and you should get an answer and explanation from s0cratic.
What is the scale factor of this dilation?
Answer:
5/3
Step-by-step explanation:
on both sides we can see that the orginal length of 3 increased to five
therfore if we multiply 3 by 3/5 we get five which means the scale factor is 5/3
Point R divides PG in the ratio 1:3. If the x-coordinate of R is -1 and the x-coordinate of P is -3, what is the x-coordinate of Q
Answer:
option C . 5
Step-by-step explanation:
For two points (x1,y1) and (x2,y2) divided by a point p in ratio m:n then coordinates of that point is given by
p : (nx1+mx2)/(m+n), (ny1+my2)/(m+n),
Given
x coordinate of P (-3)
x coordinate of Q (a) since we have to find it , let it be a
x coordinate of R(-1)\
ratio = 1:3
_______________________________________
Using the above formula to find the point of division
we can get value of x coordinate for point Q
x coordinate of R = 3*-3 + 1*a/(1+3)
-1 = (-9 + a)/4
=> -4 = -9 +a
=>a = -4+9 = 5
Thus, x coordinate of Q is 5
What numbers are equivalent to 25%
Answer:
0.25 decimal
1/4 decimal
Step-by-step explanation:
URGENT At Garcia's Bike Rentals, it costs $ 36 to rent a bike for 9 hours. How many hours of bike use does a customer get per dollar?
Answer:
.25 hour / dollar
Step-by-step explanation:
We want hours per dollar
9 hours/ 36 dollars
1/4 hour / dollar
x = 4 7 9 I dont mind for a step by step
Answer:
[tex]\boxed{\sf x = 9}[/tex]
Step-by-step explanation:
According to chord-chord theorem:
=> [tex]x* 2 = 3 * 6[/tex]
=> [tex]2x = 18[/tex]
Dividing both sides by 2
=> x = 18/2
=> x = 9
1. What is sin(A)?
1
T
2
2. What is
tan(B)?
5
3
4
13
12
이
3. What is
cos(C)?
5
3
B
5
6
4. What is
cos(D)?
7
AddP
Answer:
Sin A=0.6
Tan B = 1.3333
Cos C= 0.9231
Cos C= 0.3846
Step-by-step explanation:
For sin A
Sin A= opposite/hypotenuse
Sin A= 3/5
Sin A=0.6
For Tan B
Tan B = opposite/adjacent
Tan B = 4/3
Tan B = 1.3333
For cos C
Cos C = adjacent/hypotenuse
Cos C= 12/13
Cos C= 0.9231
For Cos D
Cos D= adjacent/hypotenuse
Cos C = 5/13
Cos C= 0.3846
