I need help with this
I need help plz!!!!!! Will give 100 points.
Point-Slope Form: y - 5 = 3(x - 1)
Standard Form: ???? HELP
In a sample of 80 light bulbs, the mean lifetime was 1217 hours with a standard deviation of 52 hours. a. Find the 95% confidence interval for the mean lifetime of this type of bulb. Justify the reason you chose the distribution used to construct the confidence interval. b. How many light bulbs must be sampled so that a 95% confidence interval will specify the mean lifetime to within + 8 hours?
Complete Question
In a sample of 80 light bulbs, the mean lifetime was 1217 hours with a standard deviation of 52 hours. a. Find the 95% confidence interval for the mean lifetime of this type of bulb. Justify the reason you chose the distribution used to construct the confidence interval. b. How many light bulbs must be sampled so that a 95% confidence interval will specify the mean lifetime to within [tex]\pm 8 \ hours[/tex]?
Answer:
a
[tex]1206 < \mu < 1228 [/tex]
The reason why a normal distribution was chosen is because the sample size is large enough that is [tex]n > 30[/tex]
b
[tex]n =162 [/tex]
Step-by-step explanation:
From the question we are told that
The sample size is n = 80
The sample mean is [tex]\= x = 1217[/tex]
The standard deviation is [tex]\sigma = 52[/tex]
From the question we are told the confidence level is 95% , hence the level of significance is
[tex]\alpha = (100 - 95 ) \%[/tex]
=> [tex]\alpha = 0.05[/tex]
Generally from the normal distribution table the critical value of is
[tex]Z_{\frac{\alpha }{2} } = 1.96[/tex]
Generally the margin of error is mathematically represented as
[tex]E = Z_{\frac{\alpha }{2} } * \frac{\sigma }{\sqrt{n} }[/tex]
=> [tex]E = 1.96 * \frac{ 52}{\sqrt{80} }[/tex]
=> [tex]E = 11.395 [/tex]
Generally 95% confidence interval is mathematically represented as
[tex]\= x -E < \mu < \=x +E[/tex]
=> [tex]1217 -11.395 < \mu < 1217 + 11.395[/tex]
=> [tex]1206 < \mu < 1228 [/tex]
Generally the sample size is mathematically represented as
[tex]n = [\frac{Z_{\frac{\alpha }{2} } * \sigma }{E} ] ^2[/tex]
Here E = 8
=> [tex]n = [\frac{1.96 * 52 }{8} ] ^2[/tex]
=> [tex]n =162 [/tex]
Assume that the population proportion is 0.46. Compute the standard error of the proportion, σp, for sample sizes of 500,000; 1,000,000; 5,000,000; 10,000,000; and 100,000,000. (Round your answers to five decimal places.)sample size of 500,000 __________sample size of 1,000,000_________sample size of 5,000,000_________sample size of 10,000,000_________sample size of 100,000,000 ___________
Answer:
a) 0.00070
b) 0.00050
c) 0.00022
d) 0.00016
e) 0.00005
Step-by-step explanation:
Standard error for proportion formula
S.E = √P(1 - P)/n
Where P = proportion
n = number of samples
Assume that the population proportion is 0.46. Compute the standard error of the proportion, σp, for sample sizes of a) 500,000
S.E = √P(1 - P)/n
= √0.46 × 0.54/500000
= √ 4.968 ×10^-7
= 0.0007048404
≈ 0.00070
b) 1,000,000
√P(1 - P)/n
= √0.46 × 0.54/1000000
= 0.0004983974
≈ 0.00050
c) 5,000,000
√P(1 - P)/n
= √0.46 × 0.54/5000000
= √ 4.968 ×10^-8
= 0.0002228901
≈ 0.00022
d) 10,000,000
√P(1 - P)/n
= √0.46 × 0.54/10000000
= √2.484 ×10^-8
= 0.0001576071
≈ 0.00016
e) 100,000,000
√P(1 - P)/n
= √0.46 × 0.54/100000000
= √2.484 × 10^-9
= 0.0000498397
= 0.00005
In a group of 20 students, there are 7 boys. What is the ratio of girls to boys?
Answer: percent is 0.53%
The ratio is 7 to 13 so you just divide 7/13
Step-by-step explanation:
which two triangles are congruent? complete the congruence statement.
Please help with the problem in the picture ^ I’ll give brainliest if you give me a small explanation! :)
Answer:
A
Step-by-step explanation:
Because when you see X and Y, x multiplied by -6 is equal to y so if you check -84/-6, your correct answer should be 14 also A, hopefully this gave you the explanation you were looking for!!!!!!!!
We have a bag that contains 100 balls, 50 of them red and 50 blue. Select 5 balls at random. What is the probability that 3 are blue and 2 are red?
Answer:
Likely, I think I havent been in this for a long time so i may be a little rusty. But anyways, I hope this helped!
Step-by-step explanation:
32% is the probability that 3 are blue and 2 are red.
What is probability?Probability can be defined as the ratio of the number of favorable outcomes to the total number of outcomes of an event.
here, we have,
We have a bag that contains 100 balls, 50 of them red and 50 blue.
We, Select 5 balls at random.
the probability that 3 are blue and 2 are red = 50C3*50C2/50C5
solving we get,
19600*1225/75287520
=24010000/75287520
=0.32
=32%
Hence, 32% is the probability that 3 are blue and 2 are red.
To learn more on probability click:
brainly.com/question/11234923
#SPJ2
Estimate the:
length of a pen
length of a swimming pool
length of a marathon race
5.2 inches 13.12 cm
length of a swimming pool:50m
length of a marathon race:42.195 kilometers
hope this answers your question!A rose bush was 2 feet tall when Candace planted it. The rose bush
grew 1 (1/4) feet per year. The rose bush is now 8 (1/4) feet tall.
Answer:
5 years
Step-by-step explanation:
Alr. The equation is:
x= how long the rose bush took to grow
8 1/4=2+1 1/4x
6 1/4=1 1/4x
5=x
I'll braintlist!!!
Find the value of each expression in lowest terms:
1/6 X 11/4
11/5 X 1/3
14/3 X 1/5
5/3 X 2/5
3/4 X 8/9
5/2 X 2/7
please help and I will mark big brain
what is the missing value in the table below?
The missing number in the given table is 180 minutes.
To find the value of x in the equation 2/120 = 3/x, we can use cross multiplication.
First, we multiply both sides of the equation by 120
(2/120) * 120 = (3/x) * 120
To simplify, we have:
2 = 3 * (120/x)
2/3 = (120/x)
To solve for x, we can multiply both sides of the equation by x:
(x) * (2/3) = (120/x) * (x)
2x/3 = 120
To isolate x, we can multiply both sides of the equation by 3/2:
(2x/3) * (3/2) = 120 * (3/2)
x = 180
Therefore, the value of x in the equation 2/120 = 3/x is x = 180.
Learn more about equations here;
https://brainly.com/question/25180086
#SPJ6
4n-(7-6n)
Helppp plz
Which statement about the diagram is true
Answer:
AB have the length of 9
Step-by-step explanation:
5 is to short 14 is too long in between would be 9
Solve each equation. y + 20 = 7
Answer:
I Meant y = -13
Step-by-step explanation:
Answer:
y= -13
Step-by-step explanation:
-13 plus 20 is 7
plug the -13 in where the y is and do the equation
-13+20=7
The data from the U.S. Census Bureau for 1980-2010 shows that the median weekly earnings of full-time
male employees who have at least a bachelor's degree can be modeled by the function
M(x) = 0.009x3 - 0.29x2 + 30.7x + 439.6 where x Is the number of years after 1980 and M(x) Is the
median weekly earnings in dollars. The median weekly earnings of all full-time employees who have at
least a Bachelor's degree can be modeled by the function T(x) = 0.012x3 - 0.46x2 + 56.1x + 732.3 where
x Is the number of years after 1980 and T(x) Is the median weekly earnings in dollars.
Estimate the median weekly earnings of a full-time female employee with at least a Bachelor's degree in
2006. Round to the nearest dollar.
The median weekly earnings of a female employee in 2006 is about
Answer:
890.908
Step-by-step explanation:
Given that :
Median weekly salary for males :
M(x) = 0.009x3 - 0.29x2 + 30.7x + 439.6
x = number of years after 1980
Median weekly salary for all employees :
T(x) = 0.012x3 - 0.46x2 + 56.1x + 732.3
Estimate the median weekly earnings of a full-time female employee with at least a Bachelor's degree in 2006
Estimated median weekly earning for a full time female employee with at least bachelor's degree ; F(x)
F(x) = T(x) - M(x)
F(x) = (0.012x3 - 0.46x2 + 56.1x + 732.3) - (0.009x3 - 0.29x2 + 30.7x + 439.6)
F(x) = (0.012 - 0.009)x3 + (-0.46 + 0.29)x2 + (56.1 - 30.7)x + (732.3 - 439.6)
F(x) = 0.003x³ - 0.17x² + 25.4 + 292.7
x = 2006 - 1980 = 26
F(26) = 0.003x³ - 0.17x² + 25.4x + 292.7
0.003(26)^3 - 0.17(26)^2 + 25.4(26) + 292.7 = 890.908
=
Two-thirds of the fruit in a basket are apples. One-fourth of the apples are green apples. What fraction of the fruit in the basket are green apples?
Answer:
1/6
Step-by-step explanation:
2/3*1/4
=2/12
=1/6
PLS GIVE BRAINLIEST
Suppose that the log-ons to a computer network follow a Poisson process with an average of three counts per minute.
Required:
a. What is the mean time between counts?
b. What is the standard deviation between counts (in minutes)?
c. If it is an average of 3 counts per minute, find the value of x such that P(X < x) = 0.95
Answer:
a. E(X) = 0.333 minutes
b. [tex]\mathbf{\sigma_x =0.333 \ minutes}[/tex]
c. 0.9986
Step-by-step explanation:
a.
To find the mean time between counts
Let X be the random variable that illustrates the time between the successive log-ons, then X is exponential with the rate [tex]\lambda = 3[/tex] log-ons per minute.
i.e.
[tex]E(X) = \dfrac{1}{\lambda}[/tex]
[tex]E(X) = \dfrac{1}{3}[/tex]
E(X) = 0.333 minutes
b. Since X is attributed to an exponential distribution, The standard deviation between counts is:
[tex]\sigma_x = \dfrac{1}{3}[/tex]
[tex]\mathbf{\sigma_x =0.333 \ minutes}[/tex]
c.
Given that;
The average number of count per minute = 3
The value of X such that P(X < x) = 0.95 can be calculated as;
[tex]\int \limits ^x_0 \lambda e^{-\lambda t}= 0.95[/tex]
[tex]3\int \limits ^x_0 \lambda e^{3 t}= 0.95[/tex]
[tex]\bigg [ -e^{3t}\bigg ]^x_0 = 0.95[/tex]
[tex]e^{3t} = 1-0.95[/tex]
-3x = ㏑ (0.05)
-3x = - 2.9957
x = -2.9957/ -3
x = 0.9986
The value of x = 0.9986
Answer:
a) 3
b)3
c) 8.9872
Step-by-step explanation:
a) According to the question, mean is 3.
b) Since it is an exponential distribution, standard deviation equals to mean. Therefore, the answer is 3.
c) P[x<X]=0.95
f(x)= λ*e^(-λ*x)
∫f(x)dx, 0 to x
mean = 1/λ =3. So, λ= 1/3.
∫(1/3)*e^(-x/3)dx= 1/3*e^(-x/3)/(-1/3)=-e^(-x/3) 0 to x
-e^(-x/3)+1 = 0.95
-e^(-x/3)=-0.05
x/3=ln(0.05)
x=ln(0.05)*3= 8.9872
During November, $83 was spent on travel. In December, $65 was spent on travel. How much was the percent of decrease? Round to the nearest tenth of a percent.
Pls Help
Answer:
Percent decrease is 21.7%
Step-by-step explanation:
The percent decrease is calculated as:
[tex]Decrease\ percentage = \frac{decrease}{Original\ quantity} * 100[/tex]
Given in the question that:
Cost on travel during November = $83
Cost on travel during December = $65
The percent decrease will be calculated by computing decrease(subtracting the cost of December from the cost of November.
[tex]Decrease = Travel\ cost\ in\ November - Travel\ cost\ in\ december\\Decrease = \$83-\$65\\= \$18[/tex]
Now, for percentage decrease
[tex]Percentage\ decrease = \frac{decrease}{Travelling\ cost\ in\ November} * 100\\=\frac{18}{83} * 100\\=21.686..[/tex]
Rounding off to nearest tenth of percent, we get the percentage decrease as 21.7%
Hence,
Percent decrease is 21.7%
What is an equation for the line that passes through the points (-2, 3) and (2, 1)
6. a) Round 50.24 to the nearest whole number. Draw a number line to show your thinking.
Answer:
50
I've attached the drawing of my number line to show my thinking. Download to turn it in if you need to.
Have a beautiful day, and stay safe.
You have a ribbon that is 7 1/2 inches long you use 1/2 of it on a project how many inches of ribbon are left
Which equation has a solution of 54.73 for n?
n +8 = 62.73
n - 8 = 62.73
62.73 + 8 = n
8-46.73 = n
Answer:
n + 8 = 62.73
the first one
Step-by-step explanation:
HELP ME ASAP!
What is the result when the number 44 is decreased by 75%?
Answer:
11
Step-by-step explanation:
Find the coordinates of the reflection: B (7,-1) is reflected over the x-axis B’=?
Answer:
(7;1)
Step-by-step explanation:
The abscissa of B' is going to be the same as abscissa of B , becuse the points are simmetrical over axis x.
However the ordinate of the point B' will have the opposite sign as ardinate B. However the module of ordinate B' is going to be the same as module of orrdinate B.
what function best models the data and what wil be the chicken breast after 50 miutes
Answer:
Students use linear, quadratic, and exponential functions to model data from tables and choose the regression
most appropriate to a given context. They use the correlation coefficient to determine the accuracy of a
regression model and then interpret the function in context. They then make predictions based on their model
and use an appropriate level of precision for reporting results and solutions.
Lesson 7 focuses on data sets that cannot be modeled accurately, and students are asked
to articulate why. Students use skills learned in Lesson 14 of Module 2 (where they used
calculators to write linear regressions) and apply similar techniques for data sets that are
better suited to modeling with quadratic or exponential regressions. Students use that
same technique to find linear regressions and use their graphing calculators to examine
the correlation coefficient and to find quadratic and exponential regressions. They
compare correlation coefficients to determine which model is best for the data.
Ultimately, students choose the regression model (linear, quadratic, or exponential) most
appropriate to a given data set and then write, verify, and interpret these models in
context. Students need a graphing calculator to complete this lesson. Graphing calculator
instructions are provided, but steps may vary slightly depending on the model of the
graphing calculator.
Refer to the following full modeling cycle during this lesson (Found on page 61 of the CCLS
and page 72 of the CCSSM).
Scaffolding:
Students are more
engaged when working
with relevant and real data
that interests them.
Websites that provide
data sets are a good
resource for classroom
investigations.
This lesson might need to
be divided into two days if
students need more time
to master the technology.
Step-by-step explanation:
SECTION 1-1 PRACTICE
Employee
Regular
Hourly Rate
х
Hours
Worked
Straight-Time
Pay
Ix
36
X Х
X Х
Wright, S.
Reardon, E.
Levitt, R.
Maguire, M.
Reyes, A.
Vadola, G.
$ 8.00
7.50
16.20
10.25
14.525
26.675
IX Х
18
30
243
31.125
25.625
X Х
You earn $6.50 per hour and work 30 hours this week. What is your straight-
Answer:
Your straight-time pay is $195.
Step-by-step explanation:
a) Data and Calculations:
Employee Regular Hourly Rate х Hours Worked = Straight-Time Pay
Wright, S. $8.00 36
Reardon, E. 7.50 18
Levitt, R. 16.20 30
Maguire, M. 10.25 243
Reyes, A. 14.525 31.125
Vadola, G. 26.675 25.625
b) If you earn $6.50 per hour and work 30 hours this week, your straight-time pay is $195 ($6.50 * 30). The straight-time pay is determined by multiplying the number of hours worked in a period by the hourly rate.
a city depatment uses an average of 25 10cent,35 15 cent and 350 20 cent postage stamps each day.the total cost of stamps used by the department in a 5 day period is
-1,000 -999 < > or = and why
Answer:
-1,000
Step-by-step explanation:
Answer:
The answer is -1,000 > -999
Step-by-step explanation:
That is because the more further you go away from the zero into the negatives on a number line graph, the bigger the number with a negative sign is, that considered smaller