Answer:
The null hypothesis is [tex]H_0: p = 0.4[/tex]
The alternative hypothesis is [tex]H_a: p < 0.4[/tex]
Step-by-step explanation:
As of 2012, the proportion of students who use a MacBook as their primary computer is 0.4.
At the null hypothesis, we test if the proportion is of 0.4, that is:
[tex]H_0: p = 0.4[/tex]
You believe that at your university the proportion is actually less than 0.4.
This means that at the alternative hypothesis, we test if the proportion is less than 0.4, that is:
[tex]H_a: p < 0.4[/tex]
Please help me i will give you brainlest
Answer:
Step-by-step explanation:
5 ) c
6) c
7) b
8) a
19. In a random sample of 250 students, we found that 75 work out 4 or more times a week. Find the 95% confidence interval for the proportion of students who work out 4 or more times a week.
Answer:
The 95% confidence interval for the proportion of students who work out 4 or more times a week is (0.2432, 0.3568).
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].
In a random sample of 250 students, we found that 75 work out 4 or more times a week.
This means that [tex]n = 250, \pi = \frac{75}{250} = 0.3[/tex]
95% confidence level
So [tex]\alpha = 0.05[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].
The lower limit of this interval is:
[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.3 - 1.96\sqrt{\frac{0.3*0.7}{250}} = 0.2432[/tex]
The upper limit of this interval is:
[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.3 + 1.96\sqrt{\frac{0.3*0.7}{250}} = 0.3568[/tex]
The 95% confidence interval for the proportion of students who work out 4 or more times a week is (0.2432, 0.3568).
3. university dean of students wishes to estimate the average number of hours students spend doing homework per week. The standard deviation from a previous study is 4 hours. How large a sample must be selected if he wants to be 96% confident of finding whether the true mean differs from the sample mean by 2 hours
Answer:
A sample of 17 must be selected.
Step-by-step explanation:
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 - 0.96}{2} = 0.02[/tex]
Now, we have to find z in the Z-table as such z has a p-value of [tex]1 - \alpha[/tex].
That is z with a pvalue of [tex]1 - 0.02 = 0.98[/tex], so Z = 2.054.
Now, find the margin of error M as such
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.
The standard deviation from a previous study is 4 hours.
This means that [tex]\sigma = 4[/tex]
How large a sample must be selected if he wants to be 96% confident of finding whether the true mean differs from the sample mean by 2 hours?
A sample of n is required.
n is found for M = 2. So
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
[tex]2 = 2.054\frac{4}{\sqrt{n}}[/tex]
[tex]2\sqrt{n} = 2.054*4[/tex]
Simplifying both sides by 2:
[tex]\sqrt{n} = 2.054*2[/tex]
[tex](\sqrt{n})^2 = (2.054*2)^2[/tex]
[tex]n = 16.88[/tex]
Rounding up:
A sample of 17 must be selected.
What value of b will cause the system to have an infinite number of solutions?
V = 6x + b
-3 x + 1/2 V = -3
Answer:
-6
Step-by-step explanation:
V = 6x + b
1/2 V -3 x = -3
V - 6x = -6
V - 6x = b
what quadratic expression represents (2x+5)(7-4x)
a.-8x^2+6x-35
b.-8x^2-34x+35
c.-8x^2+34x-35
d.-8x^2-6x+35
[tex]\\\\\\[/tex]
Therefore
[tex]\sf{Option~ D ~is ~correct }[/tex][tex]\sf{ }[/tex]
[tex]\sf{ }[/tex]
[tex]\sf{ }[/tex]
[tex]\sf{ }[/tex] [tex]\sf{ }[/tex] [tex]\sf{ }[/tex] [tex]\sf{ }[/tex] [tex]\sf{ }[/tex]
Answer:
-8x² -6x + 35
Step-by-step explanation:
A expression is given to us and we need to find out the quadratic equation . For that Multiply the two terms of the quadratic equation. The given expression is ,
Given expression :-
[tex]\rm\implies ( 2x +5)( 7 - 4x ) [/tex]
Multiply the terms :-
[tex]\rm\implies 2x ( 7 - 4x )+5(7-4x) [/tex]
Simplifying the brackets :-
[tex]\rm\implies 14x - 8x^2 + 35 - 20x [/tex]
Rearrange and simplify :-
[tex]\rm\implies -8x^2 -6x + 35 [/tex]
Therefore :-
[tex]\rm\implies\boxed{ \rm Quadratic\ Equation \ = -8x^2 -6x + 35} [/tex]
-09
2 1 point
The amount of a radioactive substance y that remains after t years is given by the equation y = a (e)^kt, where a is the initial
amount present and k is the decay constant for the radioactive substance. If a = 100, y = 50, and k = -0.035, find t.
Answer:
19.80
Step-by-step explanation:
Given the equation :
y = a (e)^kt
If a = 100, y = 50, and k = -0.035, find t.
50 = 100(e)^(-0.035t)
50/100 = e^(-0.035t)
0.5 = e^-0.035t
Take the In
In(0.5) = - 0.035t
-0.693147 = - 0.035t
-0.693147 / - 0.035 = t
19.8042 = t
Hence, t = 19.80
According to the WHO report, girls who are one month old have a mean head circumference of 36.6 centimeters with a standard deviation of 1.2 centimeters. As with most body measurements, head circumference has a normal probability distribution. Medscape defines microcephaly (small head syndrome) as a head circumference that is more than two standard deviations below the mean. What is the probability that a one-month old girl will be categorized as having microcephaly
Answer:
0.0228 = 2.28% probability that a one-month old girl will be categorized as having microcephaly
Step-by-step explanation:
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Medscape defines microcephaly (small head syndrome) as a head circumference that is more than two standard deviations below the mean. What is the probability that a one-month old girl will be categorized as having microcephaly?
Probability of a z-score of -2 or less, which is the p-value of Z = -2.
Looking at the z-table, Z = -2 has a p-value of 0.0228.
0.0228 = 2.28% probability that a one-month old girl will be categorized as having microcephaly
which is the correct answer?
Answer:
11/12
Step-by-step explanation:
1/4 + 2/3
= 3/12 + 8/12
= 11/12
the mean of 5 numbers is 198. the numbers are in ratio 1:2:3:4:5 find the smallest number
Answer: 13.2
In fraction form, this is 66/5
=============================================================
Explanation:
The five values are in the ratio 1:2:3:4:5 which scales up to 1x:2x:3x:4x:5x for some positive number x.
Add up the pieces of the second ratio and set that sum equal to 198. Then solve for x.
1x+2x+3x+4x+5x = 198
15x = 198
x = 198/15
x = 66/5
x = 13.2 is the smallest number since 1x = 1*13.2 = 13.2 was the smallest value of the ratio 1x:2x:3x:4x:5x.
Bateman Corporation sold an office building that it used in its business for $800,800. Bateman bought the building 10 years ago for $599,600 and has claimed $201,200 of depreciation expense. What is the amount and character of Bateman's gain or loss?
Answer:
$402.700 capital gain
Step-by-step explanation:
Ted is not particularly creative. He uses the pickup line "If I could rearrange the alphabet, I'd put U and I together." The random variable x is the number of women Ted approaches before encountering one who reacts positively. Determine whether a probability distribution is given. If a probability distribution is given, find its mean and standard deviation. If a probability distribution is not given, identify the requirements that are not satisfied. Find the mean of the random variable x. Select the correct choice below and, if necessary, fill in the answer box to complete your choice.
Answer:
No, the sum of all the probabilities is not equal to 1.
Step-by-step explanation:
Given
[tex]\begin{array}{ccccc}x & {0} & {1} & {2} & {3} & {P(x)} & {0.001} & {0.007} & {0.033} & {0.059} \ \end{array}[/tex]
Required
Determine if the given parameter is a probability distribution
For a probability distribution to exist, the following must be true;
[tex]\sum P(x)=1[/tex]
So, we have:
[tex]\sum P(x) = 0.001 + 0.007 + 0.033 + 0.059[/tex]
[tex]\sum P(x) = 0.1[/tex]
Hence, it is not a probability distribution because the sum of all probabilities is not 1
Which of the following is a correctly written algebraic equation?
a + 0.2x
5b - 5x + 2
a- 3x = 0
The equation "a - 3x = 0" is correctly written because it follows the standard format of an algebraic equation.
Given that,
All the equations are,
1. a + 0.2x
2. 5b - 5x + 2
3. a - 3x = 0
Now, from equation ''a - 3x = 0'',
In this equation, the variable "a" subtracted from 3 times the variable "x" equals zero.
The equal sign (=) indicates that the expression on both sides of the equation is equivalent.
The equation is properly balanced and expresses equality between the two sides.
It accurately represents a relationship between the variables "a" and "x" where the value of "a" is dependent on the value of "x" in order to satisfy the equation.
So, The correctly written algebraic equation is:
a - 3x = 0
To learn more about the equation visit:
brainly.com/question/28871326
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After deduction of 4 paisa in a Rupee a sum of Rs 720 is left.What was it originally?
Given:
After deduction of 4 paisa in a Rupee a sum of Rs 720 is left.
To find:
The original amount.
Solution:
We know that,
1 Rs. = 100 paisa
After deduction of 4 paisa in a Rupee, we get
[tex]100-4=96[/tex]
It means Rs. 720 is the 96% of the original amount.
Let x be the original amount.
[tex]720=\dfrac{96}{100}x[/tex]
[tex]72000=96x[/tex]
[tex]\dfrac{72000}{96}=x[/tex]
[tex]750=x[/tex]
Therefore, the original amount is Rs. 750.
The Cougar Swim Club acquired some Speedo Fastskin bodysuits and decided to test them out. A number of the club's fastest swimmers performed a 50m freestyle swim in a regular spandex bodysuit and in a Speedo Fastskin suit. The table below summarizes their times in seconds.Swimmer Spandex Speedo Fastskin1 31.1 29.12 28.9 30.43 31.4 32.04 34.9 31.75 27.7 28.26 36.7 32.97 33.3 28.68 30.8 26.2Perform a t-test for dependent means to determine if there is a difference between the regular spandex suit and the Fastskin bodysuit in terms of performance.t = _____df = _____Critical value of t = _____ (use alpha = 0.05)Would you reject the null hypothesis?
Answer:
T = 2.215
df = 7
Critical value = 2.364
Fail to reject the null
Step-by-step explanation:
Swimmer __Spandex __Speedo Fastskin__ d
1 __________31.1 _______29.1 __ 2
2_________ 28.9 ______30.4 __ -1.5
3_________ 31.4 ______ 32.0 __ - 0.6
4_________ 34.9 ______31.7 __ 3.2
5 _________27.7 ______28.2 __ - 0.5
6_________ 36.7 _____ 32.9 ___ 3.8
7 _________ 33.3 _____28.6 ___ 4.7
8_________ 30.8 _____26.2 ___ 4.6
The mean difference = Σd / n
2, - 1.5, - 0.6, 3.2, - 0.5, 3.8, 4.7, 4.6
μd = Σd / n = 15.7 / 8 = 1.9625
Sd = standard deviation of difference = 2.5065 (using calculator)
H0 : μd = 0
H1 : μd ≠ 0
The test statistic:
T = μd / (Sd/√n)
T = 1.9625 / (2.5065/√8)
T = 2.2145574
The degree of freedom, df = n - 1 = 8 - 1 = 7
Using a Pvalue calculator :
α = 0.05
Critical value, Tcritical = 2.364 (T distribution table)
Since Test statistic < Critical value
we fail to reject H0 ;
Xét mô hình thu nhập quốc dân hai thành phần sau đây
dY/dt= 0.5(C + I – Y)
C = 0.6Y + 600
I = 0.2Y + 400.
Tìm biểu diễn của Y(t) với Y(0) = 9000. Mô hình này ổn định hay không ổn định?
Answer:
No se me puedes ayudar por fa
PLZZZ HELPP EVEN IF I HAVE TO WASTE MY POINTS JUST HELP ME
Answer:
soln,
x=63°
Step-by-step explanation:
yea , 63° is the answer you asked
Marco can paddle his canoe at a rate of 6 miles per hour on unmoving water. However, today Marco is canoeing down (with the current), and then back up (against the current), a river that's moving at a rate of 1 mile per hour, so the current affects his rate of speed. If it takes Marco 6 total hours to go x miles downstream and then return to his starting point, how far downstream does he travel?
A) 1.25 miles
B) 2.5 miles
C) 5 miles
D) 17.5 miles
Answer:
S = v1 t1 = 7 t1 traveling downstream
S = v2 t2 = 5 t2 traveling upstream
7 t1 = 5 t2
7 (6 - t2) = 5 t2 since t1 + t2 = 6
42 - 7 t2 = 5 t2
t2 = 42 / 12 = 3.5 hrs so t1 = 2.5 hrs
S = 7 t1 = 7 * 2.5 = 17.5 mi
Also, S = 5 t2 = 5 * 3.5 = 17.5 mi
Check out the attachment and help me out please!!!
Answer:
20
Step-by-step explanation:
4 + 2 + 5 + 4 + 0 + 1 + 1 + 3 = 20
How many vertices (corners) does a cube have?
How many faces does a rectangular prism have?
How many edges does a rectangular prism have?
How many edges does a square-based pyramid have?
How many vertices (corners) does a square-based pyramid have?
How many faces does a triangular prism have?
How many vertices (corners) does a triangular prism have?
kb 2021
Answer:
The answer is below
Step-by-step explanation:
a) A cube is a three dimensional solid with 6 square faces.
A cube has 8 vertices
b) A rectangular prism is a three dimensional solid with two parallel rectangular bases.
A rectangular prism has 6 faces.
c) A rectangular prism is a three dimensional solid with two parallel rectangular bases.
A rectangular prism has 12 edges.
d) A square-based pyramid is a pyramid with a square base.
A square-based pyramid has 8 edges
e) A triangular prism is a three dimensional solid with two parallel triangular bases.
A triangular prism has 5 faces.
f) A triangular prism is a three dimensional solid with two parallel triangular bases.
A triangular prism has 6 vertices.
A fair dice is rolled. Work out the probability of getting a number less than 5. Give your answer in its simplest form.
Step-by-step explanation:
4/6
=2/3
That's what I could show you
In the following please select whether a hypothesis test or a confidence interval is most appropriate.
a. A business owner wants to know what proportion of sales occur online for their store.
b. A book publisher wants to know if more than 25% of customers buy an entire book series all at once instead of as individual books.
c. A professor wants to know the proportion of students who regularly show up to class.
d. A researcher is interested in seeing if less than 50% of Americans support the tariffs on Chinese goods.
Answer:
A. Confidence interval
B. Hypothesis test
C. Confidence interval
D. Hypothesis test
Step-by-step explanation:
A hypothesis a hypothesis test is done in statistics whereby the person carrying out the test, tests an assumption concerning a population interval.
Confidence interval can be gotten from the statistics of observed data it provides a given range of values for a parameter that is not known.
A.we use the confidence interval here
B. We use the hypothesis test
C. The confidence interval is the appropriate test
D. The hypothesis would be best
Which of the following equations describes the graph?
Newborn babies: A study conducted by the Center for Population Economics at the University of Chicago studied the birth weights of 732 babies born in New York. The mean weight was 3311 grams with a standard deviation of 860 grams. Assume that birth weight data are approximately bell-shaped. Part 1 of 3 (a) Estimate the number of newborns whose weight was less than 4171 grams. Approximately of the 732 newborns weighed less than 4171 grams. Part 2 of 3 (b) Estimate the number of newborns whose weight was greater than 1591 grams. Approximately of the 732 newborns weighed more than 1591 grams. Part 3 of 3 (c) Estimate the number of newborns whose weight was between 3311 and 5031 grams. Approximately of the 732 newborns weighed between 3311 and 5031 grams.
Answer:
a) 615
b) 715
c) 344
Step-by-step explanation:
According to the Question,
Given that, A study conducted by the Center for Population Economics at the University of Chicago studied the birth weights of 732 babies born in New York. The mean weight was 3311 grams with a standard deviation of 860 gramsSince the distribution is approximately bell-shaped, we can use the normal distribution and calculate the Z scores for each scenario.Z = (x - mean)/standard deviation
Now,
For x = 4171, Z = (4171 - 3311)/860 = 1
P(Z < 1) using Z table for areas for the standard normal distribution, you will get 0.8413.Next, multiply that by the sample size of 732.
Therefore 732(0.8413) = 615.8316, so approximately 615 will weigh less than 4171For part b, use the same method except x is now 1591.
Z = (1581 - 3311)/860 = -2
P(Z > -2) , using the Z table is 1 - 0.0228 = 0.9772 . Now 732(0.9772) = 715.3104, so approximately 715 will weigh more than 1591.For part c, we now need to get two Z scores, one for 3311 and another for 5031.
Z1 = (3311 - 3311)/860 = 0
Z2 = (5031 - 3311)/860= 2
P(0 ≤ Z ≤ 2) = 0.9772 - 0.5000 = 0.4772
approximately 47% fall between 0 and 1 standard deviation, so take 0.47 times 732 ⇒ 732×0.47 = 344.
Select the line segment.
Answer:
i think you need to attach a fine for us to do so?
Step-by-step explanation:
Answer:
I can't tell you without the problem
find integer pairs for -18?
Answer:
Step-by-step explanation:
Factor pairs:
1, 18
2, 9
3, 6
[tex]z^{7}=128i[/tex]
z = ____ + ____ i
If z ⁷ = 128i, then there are 7 complex numbers z that satisfy this equation.
[tex]z^7 = 128i = 2^7i = 2^7e^{i\frac\pi2}[/tex]
[tex]\implies z=\sqrt[7]{2^7} e^{i\frac17\left(\frac\pi2+2n\pi\right)}[/tex]
(where n = 0, 1, 2, …, 6)
[tex]\implies z = 2 e^{i\left(\frac\pi{14}+\frac{2n\pi}7\right)}[/tex]
[tex]\displaystyle\implies z = 2 \left(\cos\left(\frac\pi{14}+\frac{2n\pi}7\right)+i\sin\left(\frac\pi{14}+\frac{2n\pi}7\right)\right)[/tex]
The solution to the equation x3 = 125 is: 5 -5 ±5
Answer:
x=5
Step-by-step explanation:
x^3 = 125
Take the cubed root of each side
x^3 ^ (1/3) = 125 ^ (1/3)
x = 5
5. En una fábrica se producen 3,500
plumas por 6 trabajadores, si se
suman tres más, ¿cuál será la
producción de plumas? *
Answer:
Si se suman 3 trabajadores la producción será 5250 plumas.
Step-by-step explanation:
Inicialmente tenemos 6 trabajadores, al añadir 3 trabajadores más tendríamos ahora 9 trabajadores:
[tex] 6 + 3 = 9 [/tex]
Entonces, la producción de plumas (P) sería ahora:
[tex] P = \frac{3500}{6}*9 = 5250 [/tex]
Por lo tanto, si se suman 3 trabajadores la producción será 5250 plumas.
Espero que te sea de utilidad!
Need help
What is the domain shown in the graph
Answer:
A
Step-by-step explanation:
A cylinder has a radius of 2.5 inches (in.) and a height of 11 in., as shown.
2.5 in.
11 in.
What is the surface area, in square inches, of the cylinder?
Answer:
212.06
Step-by-step explanation:
can't really explain since the formula is fricking long but trust me that's uts 212.06 in²
