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]
Which list shows the absolute values in order from least to greatest? Question 5 options: |−2.36|, |−5.98|, 6.1 0.2, |−0.3|, |0.1| |7.6|, 5.3, 1.3
Answer:
i dont know maybe you should search google. best of Luck
Step-by-step explanation:
pleaseeeeeeeeeeeeeeeeeeeeee help me i'm begging you so the questions is what is the multiplicative of 5 and 10-5k
Answer:
1/5 and -k/5+2
Step-by-step explanation:
inverse of 5= 1/5
swap the variables: y=10−5k becomes k=10−5y
Now, solve the equation k=10−5y
for y
y=−k/5+2
A quadrilateral has no pairs of parallel sides, what two shapes could it be?
Answer:
Kite
Step-by-step explanation:
Def of kite has no parallel sides
Answer:
Kite and TrapeziumStep-by-step explanation:
Each of them do not have any parallel lines or sides
Sam bought a video game console for $150. He later sold the video game console for 13/12 of price he originally paid. Which statement about the price sam sold the video game consol for is true?
Answer:
1/45
Step-by-step explanation:
Help!!!! I don't get this!!!!!!
Answer:
C
Step-by-step explanation:
One pound (lb) is equal to 16 (oz). So, if you are trying to find how many ounces are in one pound, you have to divide the number of pounds by the 16, the amount of ounces in one pound.
Compare. Select <, >, or=.
3.568 ? 3.577
Answer:
3.568 < 3.577
Step-by-step explanation:
3.568 < 3.577
So 3.577 is greater than 3.568
It’s math can you help with number 3 please?
Answer:
25
Step-by-step explanation:
16+9
Answer:
The correct should be 25.
Step-by-step explanation:
If this is incorrect let me know and I will correct it.
riddle #2
I am a five digit even number.
all of my digits are factor of 24.
4/5 of my digits are even.
The digit in my thousands place equals the perimeter of a 2×2 array.
The digits in my ten thousand places is twice the value of the digits in the hundreds place, but half the value of the digits in the thousands places.
The digit in my tens places equal the number of lines of symmetry in an isosceles triangle.
Answer:
28416
Step-by-step explanation:
No digits can be repeated
"All my digits are factors of 24" This means that the possible digits are: 1, 2, 3, 4, 6, 8
"The digits in my thousands place equals the perimeter of a 2x2 array" That would be 8
"The digits in my ten thousand places is twice the value of the digits in the hundreds place, but half the value of the digits in the thousands place" That would be 4, which also means that the ten thousands place is 2
"The digits in my tens place equal the number of lines of symmetry in an isoceles triangle" There is only 1 lines of symmetry
This means that we have 2841(?)
Because this number is even and no digits can be repeated, the only possible digits from those available is 6
Therefore the number is 28416
Sasha spent $7.00 of the $20.00 in her wallet. Which decimal represents the fraction of the $20.00 Sasha spent?
Answer:
0.7
Step-by-step explanation:
Answer:
0.35
Step-by-step explanation:
can someone help me with this
Answer:
31°
Step-by-step explanation:
If ∠dab=55° and ∠cab=24° and ∠cab+∠dac=∠dab then all you need to do is subtract 55° and 24° to get 31°
HELP! write y+4 =-2/3(x-9) in standard form
Identify the critical t. An independent random sample is selected from an approximately normal population with unknown standard deviation. Find the degrees of freedom and the critical t value t∗t∗ for the given sample size and confidence level. Round critical t values to 3 decimal places.Sample size, n Confidence level Degree of Freedom Critical value, t∗t∗5 90 13 95 22 98 15 99
Answer and Step-by-step explanation: The critical value for a desired confidence level is the distance where you must go above and below the center of distribution to obtain an area of the desired level.
Each sample has a different degree of freedom and critical value.
To determine critical value:
1) Calculate degree of freedom: df = n - 1
2) Subtract the level per 100%;
3) Divide the result by 2 tails;
4) Use calculator or table to find the critical value t*;
For n = 5 Level = 90%:
df = 4
t = [tex]\frac{1-0.9}{2}[/tex] = 0.05
Using t-table:
t* = 2.132
n = 13 Level = 95%:
df = 12
t = [tex]\frac{1-0.95}{2}[/tex] = 0.025
Then:
t* = 2.160
n = 22 Level = 98%
df = 21
t = [tex]\frac{1-0.98}{2}[/tex] = 0.01
t* = 2.819
n = 15 Level = 99%
df = 14
t = [tex]\frac{1-0.99}{2}[/tex] = 0.005
t* = 2.977
The critical values and degree of freedom are:
sample size level df critical value
5 90% 4 2.132
13 95% 12 2.160
22 98% 21 2.819
15 99% 14 2.977
Ruth's credit card has an APR of 10,91%, and it computes finance charges using the previous balance method on a
30-day billing cycle. During the April billing cycle, she made a $45.17 payment on April 10th and a $88.34 purchase on
April 17th. Her total at the start of May was $847.64. What was her balance at the beginning of April?
a $890.91
b. $797.22
C.$796.87
d. $804.47
Please select the best answer from the choices provided
Answer:
It's B trust
Step-by-step explanation:
The required balance at the beginning of April is $796.87. Option C is correct.
What is interest?Simple interest is defined as the percentage of earnings on the lending for a period of time
To determine Ruth's balance at the beginning of April, we can work backward from her total at the start of May.
Let's call Ruth's balance at the beginning of May "B".
We know that during the April billing cycle:
She made a $45.17 payment on April 10th
She made a $88.34 purchase on April 17th
The APR is 10.91%
So, B = B - $45.17 - $88.34 + (B * 0.1091 * 30 / 365)
Solving for B, we get:
B = $796.87
So, the answer is C. $796.87.
Learn more about your interest here:
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what’s the value of x?
Answer:
x = -11
Step-by-step explanation:
The sum of the angles of a triangle add to 180
x+50 + 72+ x+80 = 180
Combine like terms
2x + 202 = 180
Subtract 202 from each side
2x+202-202 = 180-202
2x =-22
Divide each side by 2
2x/2 = -22/2
x = -11
Jordan's net income for the year ended December 31, Year 2 was $200,000.
Answer:
good for her / him but uh whats the question
Can x-2 be simplified more? Why?
Answer:
No:
Step-by-step explanation:
No, there is no way to further simplify this equation, unless there is a value for x.
Answer:
No. x-2 can't.
Step-by-step explanation:
Its the same reason why you can't simplify 1+1. You could add them together, but in a case like this, where one number is unknown you can't. The number is already to its simplifiest form.
In the table, please select the product (s), by name, that has the higher percentage of being ordered.
Find the number for which:
75% is 4.5 cm
ula for a Variable
The surface area of a cone is given by the formula
S = nil + n0r2 Solve the formula for l.
0 1=S - p2
O l=S+ p2
Ol= $ - p2
TT
01 = 5 +2.
1=
TT
Answer: 80 votes
Step-by-step explanation: Solve the formula for l. A) l ... 01/18/2017. Mathematics · High School. answered. The surface area of a cone is given by the formula S = πl + πr2. ... all of the 2's are to the power of R the 5/3.14's are fractions. 2 ... Incognit-oh-no… ... and 219 more users found this answer helpful. Thanks 140. 4.7. (80 votes).
The surface area of a cone is given by the formula S = πl + [tex]\pi r^2[/tex], the formula for I will be l = S/3.14 – [tex]r^2[/tex]. The correct option is C.
What is surface area?The surface area of a three-dimensional shape is the amount of space that surrounds it.
Starting with the given formula:
[tex]S = \pi l + \pi r^2[/tex]
We want to solve for l.
First, we can isolate the term with l on one side of the equation by subtracting [tex]\pi r^2[/tex] from both sides:
[tex]S - \pi r^2 = \pi l[/tex]
Then we can divide both sides by π to isolate l:
[tex]l = (S - \pi r^2) / \pi[/tex]
Therefore, the solution is:
[tex]l = (\frac{S}{\pi} - r^2)[/tex]
Thus, the correct option is C.
For more details regarding surface area, visit:
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Your question seems incomplete, the probable complete question is:
The surface area of a cone is given by the formula S = πl + πr2. Solve the formula for l.
A) l = S – r2
B) l = S + r2
C) l = 5/3.14 – r2
D) l = 5/3.14 + r2
all of the 2's are to the power of R
the 5/3.14's are fractions
What is the median 5,7,9,10,16,17,20
Answer:
10
Step-by-step explanation:
For an odd number of values, the median is the middle value when you write the values in ascending order.
5, 7, 9, 10, 16, 17, 20
The median is 10.
Ms. Chibbaro packs 6 almonds for every 3 craisins (cranberry raisins) in her snack pack. She has 12 more almonds than craisins.
Finding the area, any help?
Answer:
Volume: x^6
Area: 6x^4
Step-by-step explanation:
volume: length x width x height
area: 6 sides of x^4 so 6x^4
if 5x+2y=20 and y=10, what is 3x?
Answer:
3x = 0
Step-by-step explanation:
Given,
y = 10
now,
5x+2y = 20
or, 5x+2×10=20
or, 5x = 20-20
or, 5x = 0
or, x = 0/5
or, x = 0
Again,
3x = 3×0 =0
answer in percent 20/80 = x/100
Alice is saving her chore money in a bank account. She makes a deposit of $13 in the first month.
Then every month, she deposits $25. Alice forms a sequence of her account balance, An where n
refers to the number of months. Which of the statements are correct about this sequence?
Select all that apply.
Answer:
Option (3) and Option (5)
Step-by-step explanation:
Alice invested $13 in the first month.
Then she deposits $25 every month.
Therefore, sequence formed by the deposit will be an arithmetic sequence.
First term of the sequence will be,
[tex]A_1=13[/tex]
Since, recursive formula formula of a sequence is given by the formula,
[tex]A_n=A_{(n-1)}+d[/tex]
Where 'd' = common difference in each term of the sequence
Recursive formula for the sequence will be,
[tex]A_n=A{(n-1)}+25[/tex]
Since, explicit formula for the arithmetic sequence is represented by the formula,
[tex]A_n=A_1+(n-1)d[/tex]
where n = number of term
d = common difference
Therefore, nth term of the sequence formed will be represented by the explicit formula,
[tex]A_n=13+(n-1)25[/tex]
[tex]A_{10}=13+(10-1)25[/tex]
= 13 + 225
= 238
[tex]A_{8}=13+(8-1)25[/tex]
= 188
[tex]A_{12}=13+(12-1)25[/tex]
= 288
Therefore, Option (3) and Option (5) will be the answer.
pls help me with long division
86÷3 =
*The divisor is 3 and the dividend is 86
First step: How many 3's can fit into 8? (8÷3)
8÷3 = 2 r 2
Second step: add a 2 above the eight in the tens place of the answer.
86÷3 = 2_
Third step: multiply 3 x 2; 3 x 2 = 6;
In this step, we put a 6 underneath the 8.
Fourth step: Subtract.
In this step, we subtract 8-6 (=2)
Fifth step: bring down the next number. In this case, it is 6.
In this step, we now have the number 26.
Sixth step: How many 3's can fit into 26? (26÷3)
26÷3 = 8 r 2
Last step: Now put an 8 in the one's place and now we have a remaining 2. That is called the remainder. We put the remainder and represent it as "r". We put r2.
I hope this was easy for you to understand!
Answer:
Step-by-step explanation:
2 8 R2
3[tex]\sqrt{86[/tex]
- 6
-------------
26
- 24
-----------
0 2
Eighteen less than 9 times a number is the same as 14 more than the number.
Comply the equation
Answer:
x=4
Step-by-step explanation:
9x-18 = x+14
9×-× = 14+18
8× = 32
X = 4
what is the meaning of function
Answer:
A relationship or expression involving one or more variables
Step-by-step explanation:
If 4/5 – 3/10 = x + 11/2, find the value of
X.
Answer:
x = 85/60 or 17/12
Step-by-step explanation:
4/5 - 3/10 = x + 11/12
=> 8/10 - 3/10 = x + 11/12
=> 5/10 = x - 11/12
=> x - 11/12 = 5/10
=> x = 5/10 + 11/12
=> x = 5 * 6 / 10 * 6 + 11 * 5 / 12 * 5
=> x = 30 / 60 + 55/60
=> x= 85/60
If my answer helped, kindly mark me as the brainleist !!
Thank You!!
Answer:
maybe -5
Step-by-step explanation:
4/5-3/10=x+11/2
1/2-11/2=x
-10=2x
x=-5
Find the present value of an annuity due that pays $4000 at the beginning of each quarter for the next 7 years. Assume that money is worth 6.2%, compounded quarterly. If $90,000 is invested in an annuity that earns 5.4%, compounded quarterly, what payments will it provide at the end of each quarter for the next 7 1/2 years?
Answer:
Step-by-step explanation:
From the first question:
We are to find PV of the annuity.
Using the formula:
Present value of Annuity = Annuity Amount × Present Value Annuity Factor i.e. PVAF (n , r)
Where , Annuity Amount = $4,000
n = No. of periods = 7 years × 4 quarters per year = 28 periods but since the first payment is at beginning of the quarter, Then, n = 27 when considered for PVAF
r = 6.2% / 4 quarters = 1.55%,
PVAF(n0,r) when first payment is at beginning of n i.e. n0 = 1 + { [1-(1+r)^ -n0 ]/r }
= 1 + { [1-(1+0.0155)^ {-27}]/0.0155 }
= 1 + [ (1 - 0.66015 ) ] / 0.0155]
= 1 + 21.926
= 22.926
PVAF(28,1.55%) = 22.926
Thus , Present Value of Annuity = $4,000 × 22.926 = $91704.00
2. Present value of Annuity due = Annuity Amount × Present Value Annuity Factor i.e. PVAF (n , r)
Present Value of Annuity = $90,000
n = No. of periods = 7.5 years × 4 quarters per year = 30 periods
r = 5.4% / 4 quarters = 1.35%,
PVAF(n,r) = [1-(1+r)^-n]/r
PVAF(n,r) = [1-(1+0.0135)^ -30]/0.0135
PVAF(30,1.35%) = (1 - 0.6688)/0.0135
PVAF(30,1.35%) = 0.3312/0.0135
PVAF(30,1.35%) = 24.53
Hence ;
$90,000 = Annuity Amount × 24.53
Annuity amount = $90,000/24.53 = $3,668.48