Answer:
a) The margin of error for a 90% confidence interval when n = 14 is 18.93.
b) The margin of error for a 90% confidence interval when n=28 is 12.88.
c) The margin of error for a 90% confidence interval when n = 45 is 10.02.
Step-by-step explanation:
The t-distribution is used to solve this question:
a) n = 14
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 14 - 1 = 13
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 13 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.9}{2} = 0.95[/tex]. So we have T = 1.7709
The margin of error is:
[tex]M = T\frac{s}{\sqrt{n}} = 1.7709\frac{40}{\sqrt{14}} = 18.93[/tex]
In which s is the standard deviation of the sample and n is the size of the sample.
The margin of error for a 90% confidence interval when n = 14 is 18.93.
b) n = 28
27 df, T = 1.7033
[tex]M = T\frac{s}{\sqrt{n}} = 1.7033\frac{40}{\sqrt{28}} = 12.88[/tex]
The margin of error for a 90% confidence interval when n=28 is 12.88.
c) The margin of error for a 90% confidence interval when n = 45 is
44 df, T = 1.6802
[tex]M = T\frac{s}{\sqrt{n}} = 1.6802\frac{40}{\sqrt{45}} = 10.02[/tex]
The margin of error for a 90% confidence interval when n = 45 is 10.02.
find the volume if the cylinder. round to the nearest tenth if nessesary.
A. 627.5m^3.
B. 843.4m^3.
C. 986.4^3.
D. 1017.9n^3
A new car is purchased for 22300 dollars. The value of the car depreciates at 7.5% per
year. To the nearest year, how long will it be until the value of the car is 7700 dollars?
Answer:I think 3 years
Step-by-step explanation:
sorry if im wrong
In circle P, BC=24ft. What is the length of arc AC?
What is the value of the expression: x2 + y2 + x - y
when x = -1 and y = 3
Question 1 options:
6
8
12
16
Answer: 6
Step-by-step explanation:
x^2+y^2+x-y
Put x=-1 and y=1
(-1)^2+(3)^2+(-1)-(3)
1+9-1-3
10-4
6
Question 3
Convert the following proportion score to a percentage: .3852
Answer:
The percentage score is 38.52%
Step-by-step explanation:
Conversion of a proportion to a percentage:
To convert from a proportion to a percentage, we multiply by 100%, that is, the decimal point is moved two positions to the right, and the percentage sign is placed in the number.
In this question:
Proportion .3852
0.3852*100% = 38.52%
The percentage score is 38.52%
A file that is 263 megabytes is being downloaded. If the download is 17.6% complete how many megabytes have been downloaded?
Answer:
46.288 megabytes
Step-by-step explanation:
megabytes that have been downloaded
= 17.6% of 263
[tex] = 0.176 \times 263 \\ = 46.288[/tex]
One consequence of the popularity of the Internet is that it is thought to reduce television watching. Suppose that a random sample of 45 individuals who consider themselves to be avid Internet users results in a mean time of 1.98 hours watching television on a weekday. Determine the likelihood of obtaining a sample mean of 1.98 hours or less from a population whose mean is presumed to be 2.35 hours.
This question is incomplete, the complete question is;
One consequence of the popularity of the Internet is that it is thought to reduce television watching. Suppose that a random sample of 45 individuals who consider themselves to be avid Internet users results in a mean time of 1.98 hours watching television on a weekday. Determine the likelihood of obtaining a sample mean of 1.98 hours or less from a population whose mean is presumed to be 2.35 hours.
Assume that the standard deviation for "time spent watching television on a weekday" is 1.93 hours.
Answer:
the likelihood of obtaining a sample mean of 1.98 hours or less is 0.0985
Step-by-step explanation:
Given the data in the question;
x" = 1.98
μ = 2.35
s = 1.93
n = 45
so, p( x" < 1.98 ) = P( (x" - μ)/(s/√n) )
we substitute in our values,
p( x" < 1.98 ) = P( (1.98 - 2.35) / (1.93/√45) )
= p( -0.37 / 0.2877
= P( - 1.29 )
from standard normal table,
P( - 1.29 ) = 0.0985
Therefore, the likelihood of obtaining a sample mean of 1.98 hours or less is 0.0985
During trimester 2 the math team gave 4 product assignments. The 4 scores were a 50, 90, 62, and 63.
What was the median score of the product assignments?
What was the average score of the product assignments?
Answer:
median = 62.5, average = 66.25
Step-by-step explanation:
50, 90 , 62 and 63
median = 50 , 62, 63, 90
62 + 63 / 2
125/2
median = 62.5
average = 50 + 90 + 62 + 63 /4
=265/4
average = 66.25
Which of the following statements about opposites is true? Choose all correct answers.
A. The opposite of 5 is −5.
B. −(−8)=−8
C. The opposite of 0 is 0.
D. −(−2)=2
Answer:
A
Step-by-step explanation:
The water works commission needs to know the mean household usage of water by the residents of a small town in gallons per day. They would like the estimate to have a maximum error of 0.14 gallons. A previous study found that for an average family the variance is 1.69 gallons and the mean is 15.9 gallons per day. If they are using a 85% level of confidence, how large of a sample is required to estimate the mean usage of water? Round your answer up to the next integer.
Answer:
A sample of 179 is needed.
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 - 0.85}{2} = 0.075[/tex]
Now, we have to find z in the Ztable as such z has a pvalue of [tex]1 - \alpha[/tex].
That is z with a pvalue of [tex]1 - 0.075 = 0.925[/tex], so Z = 1.44.
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.
A previous study found that for an average family the variance is 1.69 gallon?
This means that [tex]\sigma = \sqrt{1.69} = 1.3[/tex]
If they are using a 85% level of confidence, how large of a sample is required to estimate the mean usage of water?
A sample of n is needed, and n is found for M = 0.14. So
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
[tex]0.14 = 1.44\frac{1.3}{\sqrt{n}}[/tex]
[tex]0.14\sqrt{n} = 1.44*1.3[/tex]
[tex]\sqrt{n} = \frac{1.44*1.3}{0.14}[/tex]
[tex](\sqrt{n})^2 = (\frac{1.44*1.3}{0.14})^2[/tex]
[tex]n = 178.8[/tex]
Rounding up
A sample of 179 is needed.
6x + 30 = -6 show your work
Answer:
its x=-6
Let's solve your equation step-by-step.
6x+30=−6
Step 1: Subtract 30 from both sides.
6x+30−30=−6−30
6x=−36
Step 2: Divide both sides by 6.
6x
6
=
−36
6
x=−6
Answer:
180
Step-by-step explanation:
Help me to find the surface area pls :( :(
Answer:
154.521
Step-by-step explanation:
Have a good day!
Answer:
154.521
Step-by-step explanation:
What number is 15 less than 63?
Answer:
48
Step-by-step explanation:
Answer:
48
Step-by-step explanation:
Select the measures that are equal. Select all that apply.pls help me i beg you
BRAINLIEST STARS
Simplify:
4+ (15 – 14) X 6
O A. 65
B. 30
O c. 24
D. 10
Looking for a clan?(Gaming clan) we are looking for content creators and more! we are a positive community and we support all gamers dreams! If Your interested reply also use our hashtag #TeamEmpire.Contact for more info
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Answer:
BRAINLEST I LOVE M.INECRAFT R O B L O X
Step-by-step explanation:
4) Is( 4,-5) a solution to
y +8 > -(x + 2)
Show your work
Please eplain
Step-by-step explanation:
[tex] - 5 + 8 > - (4 + 2) \\ 3 > - 6 \\it \: is \: true[/tex]
Answer:
yes
Step-by-step explanation:
The circumference of a circle is 11 pi inches.
What is the area, in square inches, of the circle? Express your answer in terms of pi
9514 1404 393
Answer:
30.25π square inches
Step-by-step explanation:
You can use the formula for area in terms of circumference:
A = C²/(4π)
A = (11π)²/(4π) = (121/4)π = 30.25π . . . square inches
_____
You may be expected to find the radius first:
C = 2πr ⇒ r = C/(2π) = 11π/(2π) = 5.5 . . . inches
Then use the area formula:
A = πr² = π(5.5 in)² = 30.25π in²
A circular pool has a diameter of 24 feet. What is the area of the pool to the nearest tenth
of a square foot?
a) 75.4 square feet
b) 150.8 square feet
c) 452.4 square feet
d) 1,809.6 square feet
Answer:
c) 452.4 square feet
Step-by-step explanation:
HOPE THIS HELPS, MARK AS BRAINLIEST PLEASE NOT THE FILE VIRUS EXPLOITER
-3y-5=10 Show your work please, thank you.
Answer:
-5
Step-by-step explanation:
-3y = 10 + 5
-3y = 15
y = - 5
Answer:
hi
Step-by-step explanation:
-3y-5=10
-3y=10+5
-3y=15
y=15/ -3
y= -5
hope it helps
have a nice day
43.1424 divided by 8.56
Answer: 5.04
Step-by-step explanation:
HELP PLEASE!!! LOOK AG PICTURE -which table represents a quadratic function? justify your answer
Answer:
table two
Step-by-step explanation:
The increase rate for table one is constant that's why it is a linear function
In the second table, however, the increase rate increases as x increases, it is not constant; therefore, table two is a quadratic function.
Polygon STUV is reflected over the X axis and then over the Y axis to create WXYZ. Which of the following sides are congruent?
Answer:
ST and WX
Step-by-step explanation:
flipped around st and wx mathched
Answer:
ST and WX
Step-by-step explanation:
Mrs. Crosland asked students to factor the expression 28x - 8. The students offered the answers shown in the box. Which student(s) offered answer(s) equivalent to the original expression? A. only Danny B. only Irene C. both Carlos and Danny D. both Carlos and Irene
Answer:
Step-by-step explanation:
I can't see the factorisation that the students did. That is, Danny, Carlos and Irene. You either forgot to upload, or you couldn't.
However, I will factorise the expression for you, while you check you book to know who did the exact same factorisation.
28x - 8
This equation can be factorised when divided by 2, into
2(14x - 4)
At the same time, it can be factorised when divided by 4, into
4(7x - 2)
Basically, either of the students who choose between 2(14x - 4) and 4(7x - 2) is/are whom you'd pick for your answer.
Select the correct answer.
Tim works for a cell phone company and is testing their new biometric security feature.
He conducted a test in which 4,000 attempts were made to unlock the phone. Of the attempts to unlock the phone, 25% were made by someone other than the phone's
owner. The results of the test are shown in the table.
Total
Unlocked
2,418
232
Owner
Not the Owner
Total
Did Not
Unlock
582
768
3,000
1,000
4,000
2,650
1,350
What is the probability that someone who is able to unlock the phone using the biometric security feature is not the owner?
The probability that someone who is able to unlock the phone who is not the owner will be 5.8%. Then the correct option is D.
What is probability?Its basic premise is that something will almost certainly happen. The percentage of favorable events to the total number of occurrences.
Tim works for a cell phone company and is testing their new biometric security feature.
He conducted a test in which 4,000 attempts were made to unlock the phone. Of the attempts to unlock the phone, 25% were made by someone other than the phone's owner.
The results of the test are shown in the table.
Unlocked Did Not Unlock Total
Owner 2418 582 3000
Not the Owner 232 768 1000
Total 2650 1350 4000
Then the probability that someone who is able to unlock the phone using the biometric security feature is not the owner will be
P = 232 / 4000
P = 0.058
The probability in percentage will be
P = 0.058 x 100
P = 5.8%
Then the correct option is D.
More about the probability link is given below.
https://brainly.com/question/795909
#SPJ2
Answer:
8.8%
Step-by-step explanation:
I did the test.
Olaf wants to buy a guitar that costs $600. He makes $3 per day. How many days will it take Olaf to save enough money to buy the guitar
Answer:
200 days
Step-by-step explanation:
600/3 = 200
Answer:
200 days
Step-by-step explanation:
Simple: You divide the cost of the guitar by the amount he gets paid per day. Hope this helps :)
Which answer is correct? If someone is good at math, plz help asap. I Will give out Brainlist to whoever helps me.
Answer:
picture is upside down
Answer 3. Pls pls ASAP pls pls
Answer:
a) no
b) yes
c) yes
d) no
Step-by-step explanation:
Ceasar opens a bank account and makes an initial deposit of $800. The banker tells Ceasar that he is going to receive an annual rate of 10% compounded continuously on his investment. Find the bank balance assuming Ceasar leaves the account untouched for 8 years. asnwer this question using the fomula A(t) = Pe^(rt). please show work plese
Answer:
Initial Deposit= $800
Annual rate= .1%
Leaves= 8 years
8 x .1= .8
$800 x .8= $640
$800+$640= $1,440
So your answer is $1,440 is the bank balance in 8 years
Step-by-step explanation:
hope i help have a great day
I think it will be b but I don’t know
Answer:
yeah it is b
acute and scalene
Step-by-step explanation:
scalene means none of the sides equal
and also all sides are acute angles
Answer:
yep you are correct it would be answer b
Step-by-step explanation:
hope this helped you