Answer:
6 years
Step-by-step explanation:
3. P343. 13. A sociologist is interested in surveying workers in computer-related jobs to estimate the proportion of such workers who has changed jobs within the past years. (a) In the absence of preliminary data, how large a sample must be taken to ensure that a 95% confidence interval will specify the proportion to within ±0.05? (b) In a sample of 100 workers, 20 of them had changed jobs within the past year. Find a 95% confidence interval for the proportion of workers who have changed jobs within the past year. (c) Based on the data in part (b), estimate the sample size needed so that the 95% confidence interval will specify the proportion to within ±0.05.
Answer:
a) A sample of 385 must be taken.
b) The 95% confidence interval for the proportion of workers who have changed jobs within the past year is (0.1216, 0.2784).
c) A sample of 246 is needed.
Step-by-step explanation:
Question a:
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 zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].
The margin of error is:
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
Absence of preliminary data:
This means that we use [tex]\pi = 0.5[/tex], which is when the largest sample will be needed.
95% confidence level
So [tex]\alpha = 0.05[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].
How large a sample must be taken to ensure that a 95% confidence interval will specify the proportion to within ±0.05?
A sample of n must be taken.
n is found when [tex]M = 0.05[/tex]. So
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
[tex]0.05 = 1.96\sqrt{\frac{0.5*0.5}{n}}[/tex]
[tex]0.05\sqrt{n} = 1.96*0.5[/tex]
Dividing both sides by 0.05
[tex]\sqrt{n} = 1.96*10[/tex]
[tex](\sqrt{n})^2 = (19.6)^2[/tex]
[tex]n = 384.16[/tex]
Rounding up,
A sample of 385 must be taken.
Question b:
In a sample of 100 workers, 20 of them had changed jobs within the past year.
This means that [tex]n = 100, \pi = \frac{20}{100} = 0.2[/tex]
The lower limit of this interval is:
[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.2 - 1.96\sqrt{\frac{0.2*0.8}{100}} = 0.1216[/tex]
The upper limit of this interval is:
[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.2 + 1.96\sqrt{\frac{0.2*0.8}{100}} = 0.2784[/tex]
The 95% confidence interval for the proportion of workers who have changed jobs within the past year is (0.1216, 0.2784).
Question c:
Same procedure as question a, just with [tex]\pi = 0.2[/tex]
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
[tex]0.05 = 1.96\sqrt{\frac{0.2*0.8}{n}}[/tex]
[tex]0.05\sqrt{n} = 1.96\sqrt{0.2*0.8}[/tex]
[tex]\sqrt{n} = \frac{1.96\sqrt{0.2*0.8}}{0.05}[/tex]
[tex](\sqrt{n})^2 = (\frac{1.96\sqrt{0.2*0.8}}{0.05})^2[/tex]
[tex]n = 245.8[/tex]
Rounding up
A sample of 246 is needed.
f(x)=x^2x+3;f(x)=-2x+12
Answer:
F
(
−
2
x
+
12
)
=
−
8
x
3
+
144
x
2
−
864
x
+
1731
Step-by-step explanation:
The length of the arc which subtends an angle 60° at
the centre of a circle of radius 3 cm is approximately
Answer:
π cm
Step-by-step explanation:
The formula for arc length (s) as a function of radius (r) and central angle Ф (in radians) is s = rФ.
In this problem r = 3 cm and Ф = 60°, and so the arc length subtended is
s = (3 cm)(π/3) = π cm
A pelican has a wingspan of 8 wholes 1/5 feet.
An eagle has a wingspan of 6 wholes 2/3 feet.
How much longer is the wingspan
of a pelican?
Answer:
The wingspan of a pelican is 1 8/15 feet longer than the wingspan of an eagle.
(1 whole 8/15 feet)
Step-by-step explanation:
We'll need to find a common denominator for the fractions. 15 is the lowest number divisible by both 5 and 3, so we'll use 15. For this problem, it's also easier to convert to improper fractions, in my opinion.
Pelican:
8 1/5 = 41/5
41/5 x 3/3 = 123/15
Eagle:
6 2/3 = 20/3
(20/3) x (5/5) = 100/15
Find the difference:
123/15 - 100/15 = 23/15 = 1 8/15
Please let me know if you have questions.
Find the zeros of ƒ(x) = (x + 2)(x – 1)(x – 3)(x + 1).
Answer:
X=-2 x=1 x=3 and x=-1
Step-by-step explanation:
When the problem asks you to find the zeros all they are asking for is the solution so to solve all you need to do is set each individual piece equal to zero.
Arnold's entire workout consisted of 10 minutes of warm up exercise, 25 minutes of lifting weights, and 15 minutes on the treadmill. What was the ratio of the number of minutes he lifted weights to the total number of minutes of his entire workout?
Add all the times together:
10 + 25 + 15 = 50 minutes total.
For the ratio divide the time for weights by total time:
25/50 which reduces to 1/2
The ratio is 1/2
Answer:
15:50 = 3:10
3:10 is the answer
PLEASE ANSWER ASAP WILL MARK BRAINLIEST!!!
Evaluate f^-2 g for f = 3 and g = 27.
a) 9
b) 1/3
c) 3
(3)^-2 (27)
the answer is C) 3
Space shuttle Challengerexploded because of O-ring failure shortly after it was launched. O-ring damage and temperature at time of launch for the 23 space shuttle flights that preceded the Challenger. The data is reproduced below.
Flights with O-ring damage 43 57 58 63 70 70 75
Flights with no O-ring damage 66 67 67 67 68 69 70 70 72 73 75 76 76 78 79 81
Is the mean launch temperature for fights with O-ring damage significantly less than for flights with no O-ring damage? Use 5% level of significance.
Answer:
The mean launch temperature for flights with O-ring damage is significantly lesser than Flights with No O-ring
Step-by-step explanation:
Let
Null hypothesis : H0 : μ1 ≥ μ2
Alternate hypothesis : Ha : μ1 < μ2
next calculate the test statistic
t = -2.312
calculate the P-value
p-value = T.DIST ( t ,df ) ( excel function )
= 0.0270
Given that P-value ( 0.020 ) < level of significance ( 0.05 ) we will not fail to reject the null hypothesis
Attached below is the detailed solution
Let the universal set U = {q, r, s, t, u, v, w, x,
y, z}; with
subsets A = (q, s, u, w, y); B = {q, s, y, z}; and C={v, w, x, y, z).
List the members of the indicated set, using set braces.
AUB
What’s the area of this polygon? Need to show work.
Thank you!
Step-by-step explanation:
area of traingle formed on right= 1/2*base*height
=1/2*5*6
= 15mi²
What us this cab someone help? 1 1-18 = 4
Answer:
Y= -72
Step-by-step explanation:
I dont know if that was the answer needed
Can Someone Please Help Me. ?
Answer: I think its A?
Step-by-step explanation:
Find the value of x.
B
10-X
3
D
E
х
2.
A
c
x = [?]
Answer:
The answer would be 4
Step-by-step explanation:
2/3=x/10-x
(cross multiply)
2(10-x)=3x
20-2x=3x
20=5x
(divide by 5)
x=4 (That would be the answer You welcome.)
Fill in the blank 4
For the given triangle the value of x = 4.
In the given figure,
The triangles, ABC and DBE are similar
Since we know that,
Triangles that are similar to one another in shape but differ in size are known as similar triangles. Squares with any side length and all equilateral triangles are examples of related objects. In other words, if two triangles are similar, their corresponding sides are proportionately equal and their corresponding angles are congruent.
Therefore, we have the proportionality,
EC/BE = AD/DB
⇒ 2/3=x/10-x
After cross multiplying
⇒ 2(10-x)=3x
⇒ 20-2x=3x
⇒ 20=5x
Divide both sides by 5, and we get,
⇒ x = 4
Hence,
The value of x = 4.
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SECONDARY MATH III // MODULE 5
MODELING WITH GEOMETRY - 5.5
Answer:
Its Spring break pls relax
Step-by-step explanation:
There are 196 people in
the Snow Bunnies Ski"
Club. They are taking
buses to Colorado
Each bus holds 60 peo-
ple. How many buses
are needed?
Answer:
they need 4 buses
60+60+60=180 that does not get you to 196 so you would add 1 more bus
which equals 4 buses
Jean puts 12 books on a shelf in random order. Three are by the same author. What is the probability that those 3 books will be next to each other?
it's one of these...
4.55%
8.33%
Answer:
4.55
Step-by-step explanation:
AEight different books were put on a shelf in random order. Calculate probability that two specific books were put near each other.
My answer: Let's divide the space on the shelf into eight slots. Let's also name our two books, "A" and "B" respectively. We have two sets of combinations - in the first set of combinations we have AB (i.e. A goes first). For example, A is put into the first slot and B is put into the second slot. Next example, A is put into the second slot and B is put into the third slot. And so on. There are 7 such AB combinations in total. By the same logic there are also 7 BA combinations. Obviously there is no overlap between said combinations, thus we can sum them up and get 14 combinations in total where books A and B are put side by side.
As for number of total combinations of books on the bookshelf, it's equal to "n!", where n is equal to 8. Why? Because in order to calculate combinations when repetitions are forbidden and order is important we use this formula:
What percent of the rectangle above is
shaded?
Which function has the largest maximum? (1 point)
Answer:
(4, -7) thats the largest maximum
You have a ten sided die. the die is rolled find the probability of the following:-
A-) P(5or odd number)
B-) P(odd or prime number)
A:1,3,5,7,9
b:2,3,5,7,
1) Which of the following is a measurement of length? *
O the amount of water in a pool
O the height of a building
how many blocks of concrete cover a sidewalk
O the amount of writing space on a page
Evaluate 4y-4, when y=3
Answer:
8
Step-by-step explanation:
4(3)-4=?
12-4=?
8=?
Answer:
The answer is 8
Step-by-step explanation:
4(3)-4
4 times 3 is 12 subtract by 4 you get 8.
The dot plot represents the number of apples picked by a family. Explain how the outlier of the data affects the statistical summary of the data.
Select the answers from the drop-down menus to complete the statements.
The mean apples picked
Choose...
because of the outlier.
The median apples picked
Choose...
because of the outlier.
The range
Choose...
because of the outlier.
Answer:
The dot plot represents the number of apples picked by a family. Explain how the outlier of the data affects the statistical summary of the data.
Select the answers from the drop-down menus to complete the statements.
The mean apples picked decreases because of the outlier.
The median apples picked decreases because of the outlier.
The range increases because of the outlier.
Step-by-step explanation:
The mean apples picked decreases because of the outlier.
The median apples picked decreases because of the outlier.
The range increases because of the outlier.
What is Dot plot?A dot plot, also called a dot chart, is a sort of simple histogram-like chart used in statistics for very small data sets where values fit into a number of discrete bins. To create a dot plot, count the number of data points in each bin and draw a stack of dots with that number of dots on top for each bin.
The number of apples gathered by a household is represented by the dot plot. Describe how the data outlier influences the statistical summary of the data.
To finish the statements, choose the appropriate answers from the drop-down menus.
Because of the outlier, the average number of apples picked lowers.
Because of the outlier, the median number of apples chosen falls.
Because of the outlier, the range expands.
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Will give brainliest
Answer:
Perpendicular
Step-by-step explanation:
Answer:
Perpendicular
Step-by-step explanation:
They form a 90 degree angle.
6х2 + 5х – 6
O (2x + 3)(3x - 2)
O (6x +1)(x - 6)
O (2x - 2)(3x + 3)
O (2x - 3)(3x + 2)
Answer15 y-int. (sety=0) 5%-15 (set x=0) x=3. 13,0).
Step-by-step explanation:
Which triangles must be congruent? Abc, fde, and gih.
Answer:
A. ΔABC, ΔFDE and ΔGIH
Step-by-step explanation:
From the given descriptions for the three triangles, it can be inferred that;
DE ≈ HI ≈ BC
AB ≈ FD ≈ GI
m<B = m<D = m<I
So that by Side-Angle-Side (SAS) relations among the triangles, the three triangles are congruent.
This implies that: ΔABC ≅ ΔFDE ≅ ΔGIH
The appropriate answer to the given question is A.
14. Solve 2/3 + 5/6 and put answer in simplest form.
A. 9/6
B.1 1/2
C 2/3
D. 7/6
Answer:
I believe it is C
Step-by-step explanation:
the answer is supposed to be 3/2 but i dont know
the length of a rectangle is 3 ft less than twice the width and the area of the rectangle is 65 ft squared find the dimensions.
The dimension of the rectangle is 10 by 6.5
How to determine the dimensions?The given parameters are:
Length, (L) = 2W - 3
Area = 65
The area of a rectangle is:
A = LW
So, we have:
LW = 65
Substitute L =2W - 3
(2W - 3)W = 65
Expand
2W^2 - 3W = 65
Rewrite as:
2W^2 - 3W - 65 = 0
Using a graphing calculator, we have:
W = 6.5
Substitute W = 6.5 in L =2W - 3
L =2 * 6.5 - 3
Evaluate
L =10
Hence, the dimension of the rectangle is 10 by 6.5
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A teacher has an annual income of $55,125.
The income tax the teacher has to pay is
6%. What is the amount of income tax in
dollars and cents that the teacher has to
pay?
FOR BRAINLIST!!
Answer:
A - 3307,50
Step-by-step explanation:
Answer:
A
Step-by-step explanation:
One number is seven more than four times another number. If the sum of the numbers is 22, find the numbers.
Answer:
the answer is actually study and you would know
Step-by-step explanation:
Answer:
3 and 19
Step-by-step explanation:
|al-|b| + IcI. if a=-8;6=-5;c=1
Pls no links and only give answer if you know it
Answer:
4Step-by-step explanation:
Given
a = -8;b = -5;c = 1Absolute value is always positive:
|al - |b| + IcI = |-8l - |-5| + I1I =8 - 5 + 1 =4