A researcher is interested in determining the average number of years new teachers remain in the classroom. If past information shows a standard deviation of 5 years, what size sample should be taken so that at 95% confidence the margin of error will be 6 months or less?
Answers
Given: error: 6 months, standard deviation = 5 years is 60 months
Step 1: find the minimal sample size ‘n’ for 95% confidence interval
1-0.95= 0.05
0.05/2= 0.025
Step 2:
1-0.025= 0.975
View attachment for more steps
Related Questions
Hillel is juggling flaming torches to raise money for charity. His initial appearence raises $500, and he raises $15 for each minuter of juggling performance. The amount R of money Hillel raises is a function of t, the length of his performance in minutes. write the functions formula
Answers
Answer:
r(t) = 15t+500
Step-by-step explanation:
Since the amount of money (r) is a function of the time (t) we will make it the y-value. t is how much time and he gets $15 a minute so we multiply t by 15. 500 is how much he gets paid for doing it. If he showed up and just left, he would still get 500.
Answer:
R=15t+500
Step-by-step explanation:
I have the same question
What’s the correct answer for this? Select the ones that apply
Answers
what are the factors of x^2+4x+3x?
Answers
Answer:
x(x+7)
Step-by-step explanation:
x^2+4x+3x
Combine like terms
x^2+7x
Factor out an x
x(x+7)
Answer:
[tex]x(x + 7)[/tex]
Step-by-step explanation:
[tex] {x}^{2} + 4x + 3x[/tex]
Combine like terms
[tex] {x}^{2} + 7x[/tex]
Factoring
[tex]x(x + 7)[/tex]
hope this helps
brainliest appreciated
good luck! have a nice day!
what is archieves meaning
Answers
Answer:
the meaning is "a collection of historical documents or records providing information about a place, institution, or group of people."
Step-by-step explanation:
hope this helped and plz mark me as brainliest!
Answer:
a collection of historical documents or records providing information about a place, institution, or group of people
Step-by-step explanation:
A total of 4.8 percent of the prime time viewing audience watched shows on ABC, 6.7 percent watched shows on CBS, 5.2 percent on Fox, 5.8 percent on NBC, 1.7 percent on Warner Brothers, and 1.9 percent on UPN. A total of 73.9 percent of the audience watched shows on other cable networks, such as CNN and ESPN. What will be the prime time viewing percentage of the pie chart for the following data? (Only consider the viewers watching non-cable news.) (Round your answers to 2 decimal places.)
Prime time viewing
ABC %
CBS %
Fox %
NBC %
Warner %
UPN %
Answers
Answer:
Prime time viewing
ABC % = 18.39%
CBS % = 25.67%
Fox % = 19.92%
NBC % = 22.22%
Warner % = 6.51%
UPN % = 7.28%
Step-by-step explanation:
We have to calculate the percentage of prime time viewing for each of the non-cable networks.
We know that 73.9% of the audience watched shows on cable networks. That left us with 26.1% of the audience for the non-cable networks.
[tex]\text{Cable\%}=1-0.739=0.261=26.1\%[/tex]
Then, if we use a pie chart only for the non-cable networks, we have to calculate the proportion of each network relative to the non-cable audience.
We can calculate that as:
[tex]\text{ABC}=0.048/0.261=0.1839=18.39\%\\\\\text{CBS}=0.067/0.261=0.2567=25.67\%\\\\\text{Fox}=0.052/0.261=0.1992=19.92\%\\\\\text{NBC}=0.058/0.261=0.2222=22.22\%\\\\\text{Warner}=0.017/0.261=0.0651=6.51\%\\\\\text{UPN}=0.019/0.261=0.0728=7.28\%\\\\[/tex]
The wattle thickness (in millimeters) of 15 randomly selected chickens was measured before and after treatment with phytohemagglutinin (PHA). Does treatment with PHA increase wattle thickness
Answers
Answer:
Step-by-step explanation:
The question is incomplete. The complete question is:
The wattle thickness (in milimeters) of 15 randomly selected chickens was measured before and after treatment with PHA. Does treatment wih PHA increase wattle thickness?
Chicken Number // Pretreatment // Posttreatment
1 // 1.05 // 3.48
2 // 1.01 // 5.02
3 // 0.78 // 5.37
4 // 0.98 // 5.45
5 // 0.81 // 5.37
6 // 0.95 // 3.92
7 // 1.00 // 6.54
8 // 0.83 // 3.42
9 // 0.78 // 3.72
10 // 1.05 // 3.25
11 // 1.04 // 3.66
12 // 1.03 // 3.12
13 // 0.95 // 4.22
14 // 1.46 // 2.53
15 // 0.78 // 4.39
Solution:
Corresponding wattle thickness before and after treatment form matched pairs.
The data for the test are the differences between the wattle thickness at pretreatment and posttreatment.
μd = wattle thickness at pretreatment minus wattle thickness at posttreatment
Pretreatment. Posttreatment diff
1.05 3.48 -2.43
1.01 5.02 -4.01
0.78 5.37 -4.59
0.98 5.45 -4.47
0.81 5.37 -4.56
0.95 3.92 -2.97
1 6.54 -5.54
0.83 3.42 -2.59
0.78 3.72 -2.94
1.05 3.25 -2.2
1.04 3.66 -2.62
1.03 3.12 -2.09
0.95 4.22 -3.27
1.46 2.53 -1.07
0.78 4.39 -3.61
Sample mean, xd
= (-2.43 - 4.01 - 4.59 - 4.47 - 4.56 - 2.97 - 5.54 - 2.59 - 2.94 - 2.2 - 2.62 - 2.09 - 3.27 - 1.07 - 3.61)/15 = - 3.264
xd = - 3.264
Standard deviation = √(summation(x - mean)²/n
n = 15
Summation(x - mean)² = (- 2.43 + 3.264)^2 + (-4.01 - 3.264)^2 + (-4.59 - 3.264)^2+ (-4.47 - 3.264)^2 + (-4.56 - 3.264)^2 + (-2.97 - 3.264)^2 + (-5.54 - 3.264)^2 + (-2.59 - 3.264)^2 + (-2.94 - 3.264)^2 + (-2.2 - 3.264)^2 + (-2.62 - 3.264)^2 + (-2.09 - 3.264)^2 + (-3.27 - 3.264)^2 + (-1.07 - 3.264)^2 + (-3.61 - 3.264)^2 = 627.32444
Standard deviation = √(627.32444/15
sd = 6.47
For the null hypothesis
H0: μd ≥ 0
For the alternative hypothesis
H1: μd < 0
1) The distribution is a students t. Therefore, degree of freedom, df = n - 1 = 15 - 1 = 14
The formula for determining the test statistic is
t = (xd - μd)/(sd/√n)
t = (- 3.264 - 0)/(6.47/√15)
t = - 1.95
We would determine the probability value by using the t test calculator.
p = 0.036
Assume alpha = 0.05
Since alpha, 0.05 > than the p value, 0.036, then we would reject the null hypothesis. Therefore, we can conclude that at a significance level of 5%, treatment with PHA increase wattle thickness
complete this sentence in a triangle the angle with the greatest measure is always opposite the
Answers
Answer:
longest side
Step-by-step explanation:
In a triangle the angle with the greatest measure is always opposite the longest side.
The toasters produced by a company have a normally distributed life span with a mean of 5.8 years and a standard deviation of 0.9 years, what warranty should be provided so that the company is replacing at most 5% of their toasters sold?
Answers
Answer:
A warranty of 4.32 years should be provided.
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.
In this question, we have that:
[tex]\mu = 5.8, \sigma = 0.9[/tex]
What warranty should be provided so that the company is replacing at most 5% of their toasters sold?
The warranty should be the 5th percentile, which is X when Z has a pvalue of 0.05. So it is X when Z = -1.645.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]-1.645 = \frac{X - 5.8}{0.9}[/tex]
[tex]X - 5.8 = -1.645*0.9[/tex]
[tex]X = 4.32[/tex]
A warranty of 4.32 years should be provided.
Which values of a,b,and c correctly represent the answer in simplest form 7/9 divied by 4/9 =
Answers
Answer:
[tex]7/4[/tex]
Solution:
[tex]\frac{7}{9} /\frac{4}{9}[/tex]
Reciprocal.
[tex]7/9(9/4)[/tex]
Multiply.
[tex]\frac{63}{36}[/tex]
Simplify
[tex]\frac{7}{4}[/tex]
Solve each system by elimination
-9x -4y=2
7x +4y = -6
Answers
Answer:
cộng vế theo vế ta đc :
-2x=-4<=>x=2
thay x=2 vào 1 trong 2 ptrình ta đc: y=-5
In two or more complete sentences, compare the number of x-intercepts in the graph of f(x) = x2 to the number of x-intercepts in the graph of g(x) = -x2 +7. Be sure to include the transformations that occurred between the parent function f(x) and its image g(x).
Answers
Answer:
Step-by-step explanation:
The function f(x) = x^2 has only one x-intercept which means only {0} is the only number that makes y zero.
The second function g(x) = (x-2)^2 -3 has also one x-intercept, {3.732} which will make the value of y, zero.
Answer:
The function started facing up with a vertex at (0, 0). Since 7 was added before squaring, the graph shifts 7 units up so the vertex at (7, 0). Also, the function is negative so the graph is pointing down
This means that there are two x-intercepts in g(x) and there was one x-intercept in f(x).
Step-by-step explanation:
used this and it was right.
How do I do this problem? Two similar pyramids have matching sides in the ratio 5:7. If the surface area of the larger pyramid is 441 cm^2. find the surface area of
the smaller pyramid.
S Area
cm²
Answers
Answer:
Surface area of the smaller pyramid will be 225 cm²
Step-by-step explanation:
Two similar pyramids have their matching or corresponding sides in the ratio of 5 : 7.
In other words,
[tex]\frac{\text{One side of the smaller pyramid}}{\text{One side of the larger pyramid}}[/tex] = [tex]\frac{5}{7}[/tex]
Therefore, [tex]\frac{\text{Surface area of the smaller pyramid}}{\text{Surface area of the larger pyramid}}[/tex] = [tex](\frac{5}{7})^{2}[/tex]
[tex]\frac{S_{\text{small}}}{S_{\text{large}}}=\frac{25}{49}[/tex]
[tex]\frac{S_{\text{small}}}{441}=\frac{25}{49}[/tex]
[tex]S_{\text{Small}}=\frac{441\times 25}{49}[/tex]
= 225 cm²
Therefore, surface area of the smaller pyramid will be 225 cm².
Please answer this correctly
Answers
Answer:
V =113.04 cm^3
Step-by-step explanation:
The volume of a cylinder is given by
V = pi r^2 h
V = 3.14 (3)^2 4
V = 3.14 *9*4
V =113.04 cm^3
Answer:
Step-by-step explanation:
3*3.14
9.42*9.42
88.7364*4
354.9456 rounded to
355
A bag has 8 red tiles and 2 green tiles. In a charity carnival game, you pay $5 to randomly pull a tile from the bag. The payout for pulling a red tile is $1 and the payout for pulling a green tile is $10. Which of the followig are true or false.
a. The expected payoff per game for the charity is $2.20.
b. In 20 games, the charity can expect to make $44.
c. In 30 games, the charity can expect to make $120.
d. In 5 games, the player can expect to lose $11.
Answers
Answer:
B:True
Step-by-step explanation:
B is true as a bag of 8 red tiles and 2 green tiles you pay 5 per tile meaning in twenty games you pay $100(50 per bag) and the total amount you win back is $56(28 per bag) so the equation would be $100 - $56= $44 profit to the charity
Hence only statement 1 is correct,∴The expected payoff per game for the charity is $2.20.
What is payoff?Money provided to someone as a bribe, reward, or when they leave a position. As a result, a mathematical function representing the award awarded to a single player at the game's conclusion has been developed.
How to Solve?Given a bag of tiles containing 8 red tiles, 2 green tiles.
Probability of drawing a red tile =1/8
Probability of drawing a green tile =1/2
If red tile is pulled payout is $1 else $10
Payout=
payout for 1 game= $1*8/10+$10*2/10-$5=2.20
payout in 20 games =$1*10*8/10+$10*10*2/10-$5*20=-72
payout for 30 games=$1*15*8/10+$10*15*2/10-$5*30=0
payout in 5 games=$1*5*8/10+10*5*2/10-$5*5=$25
Hence only statement 1 is correct, ∴The expected payoff per game for the charity is $2.20.
Learn more about probability https://brainly.com/question/14211455
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If a(x) = 2x - 4 and b(x) = x + 2, which of the following expressions produces a quadratic function?
(ab)(x)
Ol
(x)
(a - b)(x)
(a + b)(x)
Answers
Answer:
(ab)(x)
Step-by-step explanation:
The sum or difference of two linear functions will be a linear function. The product of two linear functions will be a quadratic function.
In 1970, the average length of a major league baseball game was 150 minutes compared to 180 minutes in 2018. Calculate the absolute and relative change in major league baseball game times from 1970 to 2018. Round your answer for relative change to the nearest whole percent.
Answers
Answer:
30 min20%Step-by-step explanation:
The absolute change in game length is ...
(180 min) -(150 min) = 30 min . . . . change in game length
__
The relative change is expressed as a fraction of the original game length:
(30 min)/(150 min) × 100% = 20% . . . . relative change in game length
Which equation represents the linear function that is shown on the graph below?
y = one-half x + 4
y = one-half x minus 2
y = 4 x minus 2
y = negative 2 x + 4
Answers
Answer:
A=(4,0) and B = (6,1)
We can find the slope with this formula:
[tex]m =\frac{y_2 -y_1}{x_2 -x_1}[/tex]
And replacing we got:
[tex] m= \frac{1-0}{6-4}= \frac{1}{2}[/tex]
Now we can find the y intercept using one of the points like this:
[tex] 0 = \frac{1}{2} *4 +b[/tex]
And then b would be:
[tex] b = -2[/tex]
And the equation would be given by:
[tex] y= \frac{1}{2}x -2[/tex]
And the best option is:
y = one-half x minus 2
Step-by-step explanation:
In order to find the equation for the line we can use two points and let's take:
A=(4,0) and B = (6,1)
We can find the slope with this formula:
[tex]m =\frac{y_2 -y_1}{x_2 -x_1}[/tex]
And replacing we got:
[tex] m= \frac{1-0}{6-4}= \frac{1}{2}[/tex]
Now we can find the y intercept using one of the points like this:
[tex] 0 = \frac{1}{2} *4 +b[/tex]
And then b would be:
[tex] b = -2[/tex]
And the equation would be given by:
[tex] y= \frac{1}{2}x -2[/tex]
And the best option is:
y = one-half x minus 2
Answer:
C
Step-by-step explanation:
hope this helps!
Identify the measure of arc BD.
A. 51
B. 72
C. 105
D. 129
Answers
Answer:
Option (D). 129°
Step-by-step explanation:
In the figure attached,
AB and CD are the diameters intersecting at the center of the circle F.
Central angle AFC = 129°
m([tex]\widehat{AC}[/tex]) = 129°
m(∠AFD) = 180° - (m∠AFC)
= 180° - (129)°
= 51°
Since m∠AFD = m∠BFC = 51° [Vertical angles]
Therefore, [tex]m(\widehat{AD})=m(\widehat{BC})=51[/tex]
Now, [tex]m(\widehat{BC})+m(\widehat{BD})[/tex] = 180°
51° + [tex]m(\widehat{BD})[/tex] = 180°
[tex]m(\widehat{BD})[/tex] = 180° - 51°
[tex]m(\widehat{BD})[/tex] = 129°
Therefore, Option (D) will be the answer.
What is -4 = -3 + x 8
Answers
Answer:
x=-1/8
Step-by-step explanation:
You solve this like an regular equation
Hope this Helps
Stay Safe:)
What’s the correct answer for this question?
Answers
Answer:
C
Step-by-step explanation:
Slope Formula is used from 2-5
Which is
Slope Formula = Rise/Run
Slope Formula = y₂-y₁/x₂-x₁
Golf-course designers have become concerned that old courses are becoming obsolete since new technology has given golfers the ability to hit the ball so far. Designers, therefore, have proposed that new golf courses need to be built expecting that the average golfer can hit the ball more than 230 yards on average. A random sample of 177 golfers show that their mean driving distance is 230.7 yards, with a standard deviation of 41.8.
1. Set up the null and alternative hypotheses to test for the designers belief.
a. H0 : µ ≥ 230 versus Ha : µ < 230
b. H0 : µ = 230.7 versus Ha : µ ≠ 230.7
c. H0 : µ ≥ 230.7 versus Ha : µ < 230.7
d. H0 : µ ≤ 230.7 versus Ha : µ > 230.7
e. H0 : µ ≤ 230 versus Ha : µ > 230
2. Find the value of the standardized test statistic.
a. 0.125
b. -0.125
c. 0.223
d. -0.7
e. 0.7
3. Find the P-value for the above mentioned test.
a. 0.8237
b. 0.0228
c. 0.5871
d. 0.4118
e. 0.0871
Answers
Answer:
a) e) H0 : µ ≤ 230 versus Ha : µ > 230
b) [tex]t=\frac{230.7-230}{\frac{41.8}{\sqrt{177}}}=0.223[/tex]
c. 0.223
c) [tex]p_v =P(t_{(176)}>0.223)=0.4118[/tex]
d. 0.4118
Step-by-step explanation:
Information given
[tex]\bar X=230.7[/tex] represent the sample mean
[tex]s=41.8[/tex] represent the sample standard deviation
[tex]n=177[/tex] sample size
[tex]\mu_o =230[/tex] represent the value to verify
t would represent the statistic
[tex]p_v[/tex] represent the p value
Part a
We want to verify if the true mean is higher than 230 yards, the system of hypothesis would be:
Null hypothesis:[tex]\mu \leq 230[/tex]
Alternative hypothesis:[tex]\mu > 230[/tex]
The best option would be:
H0 : µ ≤ 230 versus Ha : µ > 230
Part b
The statistic is given by:
[tex]t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}[/tex] (1)
Replacing the info given we got:
[tex]t=\frac{230.7-230}{\frac{41.8}{\sqrt{177}}}=0.223[/tex]
Part c
The degrees of freedom are:
[tex]df=n-1=177-1=176[/tex]
The p value would be given by:
[tex]p_v =P(t_{(176)}>0.223)=0.4118[/tex]
d. 0.4118
Identify the type of claim in each research question below.
For many years "working full-time" was 40 hours per week. A business researcher gathers data on the hours that corporate employees work each week. She wants to determine if corporations now require a longer work week.
Group of answer choices
a.Testing a claim about a single population proportion.
b.Testing a claim about a single population mean.
c.Testing a claim about two population proportions.
dTesting a claim about two population means.
Answers
Answer:
b.Testing a claim about a single population mean.
Step-by-step explanation:
Hello!
The researcher wants to test the claim that corporation employees work more than 40 hours per week.
The variable of interest is "The number of hours a corporate employee works per week"
The parameter of study, for her to make a valid conclusion about the weekly working hours of the population of corporation employees is the population mean μ.
If the claim is correct, she would expect the population mean of weekly hours the corporate employees work to be greater than 40.
This is an example of a single population mean test.
given B(-5 0) reflected across the line y=-2
Answers
Answer:
When it is reflected across y=-2, the new location will be at (-5,-4)
Step-by-step explanation:
y=-2 is a horizontal line. The points B(-5,0) is 2 units above that point. So, when reflected, it will move 4 units down, which gives you (-5,-4).
Answer fast i have timer
Answers
Answer:
k is equal to 42
Step-by-step explanation:
is sin 30 = 0.5, then sin-1 0.5 =30
Answers
Answer:
yes
Step-by-step explanation:
sin 30 = 0.5
sin-1 = 30
Simplify: StartRoot 64 r Superscript 8 Baseline EndRoot
Answers
Answer:
8r^4
Step-by-step explanation:
[tex]\sqrt{64r^8} =\sqrt{(8r^4)^2}=\boxed{8r^4}[/tex]
Answer:
8r^4
Step-by-step explanation:
What is the range of the function
Y = 2eX-1?
Answers
Answer:
-4293272 (y|y>-1)(y|y>-1)
Write this number in standard form 6,000,000+9000,000+80,000+9,000+500+80+2
Answers
6000000+9000009+80000+9000+500+80+2=15089591
Answer:
15089582 = 1.5089582 x 10^7
Step-by-step explanation:
6,000,000+9000,000+80,000+9,000+500+80+2 = 15089582
15089582 = 1.5089582 x 10^7
What’s the correct answer for this question?
Answers
Answer:
C
Step-by-step explanation:
PG = GO
2(4x-3)-8=4+2x
8x-6-8=4+2x
8x-14=4+2x
8x-2x=4+14
6x=18
Dividing both sides by 6
x = 3
Answer:
x = 3
Step-by-step explanation:
Since the chords are congruent then they are equidistant from the centre, thus
PG = GO , substitute values
2(4x - 3) - 8 = 4 + 2x ← distribute and simplify left side
8x - 6 - 8 = 4 + 2x
8x - 14 = 4 + 2x ( subtract 2x from both sides )
6x - 14 = 4 ( add 14 to both sides )
6x = 18 ( divide both sides by 6 )
x = 3
According to Eurostat, 55.2% of households in Italy have one child, the highest percentage in the Euro zone. A random sample of 160 Italian households was selected. The standard error of the proportion is ________.
Answers
Answer:
0.04
Step-by-step explanation:
In this case we must use the following formula to be able to find the standard error, which would be the square root, of the probability for its complement divided by the population:
SE= [tex]\sqrt{\frac{p *(1-p)}{n} } \\[/tex]
Now, knowing that p = 0.552 and n = 160 we replace and we are left with:
SE = [tex]\sqrt{\frac{0.552 *(1-0.552)}{160} } \\[/tex]
SE = [tex]\sqrt{0.00154}[/tex]
SE = 0.039
Which means that the standard error of the proportion is 0.04
