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]
At the end of week 3 of my baseball team's season, our rcord is 5 wins and 7 looses. Each week after that, we wim 3 games and lose 1 game. At the end of which week will my team have first won at least twice as many games total this season as it has lost?
Answer:
9 weeks
Step-by-step explanation:
Number of Certified Organic Farms in the United States, 2001–2008
Year Farms
2001 6,231
2002 6,574
2003 7,237
2004 7,211
2005 7,701
2006 8,581
2007 10,302
2008 11,796
Click here for the Excel Data File
(a) Fit three trends (linear, quadratic, exponential) to the time series. (A negative value should be indicated by a minus sign. Do not round the intermediate calculations. Round your final answers to 2 decimal places.)
(b) Use each of the three fitted trend equations to make numerical forecasts for the next 3 years. (Round the intermediate calculations to 2 decimal places and round your final answers to 1 decimal place.)
Answer:
ŷ = 739.49X + 4876.43
y = 6755.98 - 388.24x + 125.30x²
y = 5428.98(1.09)^x
B.)
Linear:
ŷ = 739.49(9) + 4876.43
y = 11531.8
Year 2010 ; x = 10
y = 739.49(10) + 4876.43
y = 12271.3
Year 2011 ; x = 11
y = 739.49(11) + 4876.43
y = 13010.8
Quadratic :
Year 2009 ; x = 9
y = 6755.98 - 388.24(9) + 125.30(9^2)
y = 13411.1
Year 2010 ; x = 10
y = 6755.98 - 388.24(10) + 125.30(10^2)
y = 15403.6
Year 2011 ; x = 11
y = 6755.98 - 388.24(11) + 125.30(11^2)
y = 17646.6
Exponential:
Year 2009 ; x = 9
y = 5428.98(1.09)^9
y = 11791.2
Year 2010 ; x = 10
y = 5428.98(1.09)^10
y = 12852.4
Year 2011 ; x = 11
y = 5428.98(1.09)^11
y = 14009.1
Step-by-step explanation:
X :
1
2
3
4
5
6
7
8
Y:
6231
6574
7237
7211
7701
8581
10302
11796
Using the online linear regression calculator :
The linear trend :
ŷ = 739.49X + 4876.43
Where x = year
With 2006 representing 1 ; and so on
Slope = m = 739.49
Intercept (c) = 4876.43
y = predicted variable
The quadratic model:
General form:
y = A + Bx + Cx²
y = 6755.98 - 388.24x + 125.30x²
The exponential model:
y = AB^x
y = 5428.98(1.09)^x
B.) Next three years :
Year 2009 ; x = 9
Year 2010 ; x = 10
Year 2011 ; x = 11
Linear:
ŷ = 739.49(9) + 4876.43
y = 11531.8
Year 2010 ; x = 10
y = 739.49(10) + 4876.43
y = 12271.3
Year 2011 ; x = 11
y = 739.49(11) + 4876.43
y = 13010.8
Quadratic :
Year 2009 ; x = 9
y = 6755.98 - 388.24(9) + 125.30(9^2)
y = 13411.1
Year 2010 ; x = 10
y = 6755.98 - 388.24(10) + 125.30(10^2)
y = 15403.6
Year 2011 ; x = 11
y = 6755.98 - 388.24(11) + 125.30(11^2)
y = 17646.6
Exponential:
Year 2009 ; x = 9
y = 5428.98(1.09)^9
y = 11791.2
Year 2010 ; x = 10
y = 5428.98(1.09)^10
y = 12852.4
Year 2011 ; x = 11
y = 5428.98(1.09)^11
y = 14009.1
A polling agency is investigating the voter support for a ballot measure in an upcoming city election. The agency will select a random sample of 400 voters from one region, Region A, of the city. Assume that the population proportion of voters who would support the ballot measure in Region A is 0.46.
Required:
What is the probability that the proportion of voters in the sample of Region A who support the ballot measure is greater than 0.50?
Answer:
0.0544
Step-by-step explanation:
From the given information;
The population proportion of the voters that would support the ballot measures in region A = 0.46
The random sample n = 400 voters
The required probability can therefore be computed as follows:
[tex]P[p_1>0.5] = P \bigg [ \dfrac{p_1-P_1}{\sqrt{\dfrac{P_1(1-P_1)}{n_1}}}>\dfrac{0.5-0.46}{\sqrt{\dfrac{0.46(1-0.46)}{400}}} \bigg][/tex]
[tex]P[p_1>0.5] = P \bigg [ Z>\dfrac{0.04}{\sqrt{\dfrac{0.46(0.54)}{400}}} \bigg][/tex]
[tex]P[p_1>0.5] = P \bigg [ Z>\dfrac{0.04}{\sqrt{6.21\times 10^{-4}}} \bigg][/tex]
[tex]P[p_1>0.5] = P \bigg [ Z>1.605 \bigg][/tex]
[tex]P[p_1>0.5] = 1- P [ Z<1.605 ][/tex]
Using the Excel Function =NORMDIST(1.605)
[tex]P[p_1>0.5] = 1- 0.9456[/tex]
[tex]P[p_1>0.5] =0.0544[/tex]
Therefore, the required probability = 0.0544
Consider the following experiment: Rolling a die. What is the sample space of the experiment? What is the probability of getting a 1 or a 2? a. 12 possible outcomes; P(1 or 2) = StartFraction 3 Over 12 EndFraction b. 12 possible outcomes; P(1 or 2) = One-third c. 6 possible outcomes; P(1 or 2) = One-fourth d. 6 possible outcomes; P(1 or 2) = One-third Please select the best answer from the choices provided A B C D
Answer: D
Step-by-step explanation: Edge
Answer:
It is D i think.
What is the area of the figure?
A. 36 cm2
B. 26 cm
C. 15 cm
D. 42 cm2
Help, please I need the answer
Answer: -22
Good Luck!
The expression 4x − 2(5x − 1) is equivalent to the expression 2 + 6x.
True
False
It is false that the expressions 4x − 2(5x − 1) and 6x + 2 are equivalent expressions
How to determine the true statement?The expression is given as:
4x − 2(5x − 1)
Open the bracket
4x − 2(5x − 1) = 4x − 10x + 2
Evaluate the like terms
4x − 2(5x − 1) = − 6x + 2
− 6x + 2 and 6x + 2 are not equal expressions
Hence, 4x − 2(5x − 1) and 6x + 2 are not equivalent expressions
Read more about equivalent expressions at:
https://brainly.com/question/2972832
#SPJ2
I GIVE CROWN
HELP ONLY SERIOUS HELP NOT FOR POINTS
A football Waze proximately 0.42 kg. The physical education teacher needs to purchase a dozen footballs. What will be the total weight, in kilograms, of the footballs to calculate shipping and handling?
You have found the following ages in years of 4 gorillas at your local zoo. What is the average age of the gorillas at your zoo? What is the variance? 7, 10, 15,21
Answer:
your answer is 7
Step-by-step explanation:
i may be wrong but i think that is the correct answer oh and Have a good thanksgiving everyone
Answer:
13.3 and 28.2 years
Step-by-step explanation:
from Khan academy
15 POINTS IF U ANSWER
Answer:
we need explaining of this question
Expand the following expression
(9h+2k)^2
Btw the biggest garden is the rectangular garden
Suppose the amount of a popular sport drink in bottles leaving the filling machine has a normal distribution with mean 101.5 milliliters (mL) and standard deviation 1.6. If 36 bottles are randomly selected, find the probability that the mean content is less than 102.1 mL
Answer:
0.98778
Step-by-step explanation:
When we are given a random number rod samples, we solve using z score formula
z = (x-μ)/σ/√n, where
x is the raw score = 102.1 mL
μ is the population mean = 101.5 milliliters (mL)
σ is the population standard deviation = 1.6.
n = 36
z = 102.1 - 101.5/1.6/√36
z = 2.25
Probability value from Z-Table:
P(x<102.1) = 0.98778
Hence, If 36 bottles are randomly selected, find the probability that the mean content is less than 102.1 mL is 0.98778
what is downpayment?
Answer:
Down payment is when you are trying to by something that is expensive up front like a house or a car. It is usually paid in cash or equivalent at the time of finalizing the transaction. A loan of some sort is then required to finance the remainder of the payment.
Step-by-step explanation:
What were the coordinates of point B after being translated 4 units left
Answer: B' (x-4,y)
Step-by-step explanation: A figure which is moved from one location to antoher, without changing its size, shape or orientation, is a figure that went through translation.
So, when a point is translated, it means it changed its position.
Point B has x- and y-coordinates: B(x,y)
Point B' after being translated 4 units left means:
(x,y) → (x-4,y)
In other words, translated point B has coordinates
B(x-4, y)
Because moving left is saying the point is moving towards the negative "side" of the x-axis.
Answer Choices:
A) (-6, -1)
B) (6, -1)
C) (-6, 1)
Anya is saving her allowance to purchase a bike.Anya started her savings with $10 and is saving $5 per week.Let y represent the total amount Anya has saved and x represent the number of weeks Anya has been saving.
Answer:
y = 10 + 5x
Step-by-step explanation:
The question seem incomplete as the question requirement is not stated.
However, I'll solve for the equation and also plot the graph that illustrates the equation.
From the question, we have the following.
Base Amount = 10
Additional = 5 (weekly)
Let y represents her savings at any given weeks and x represents the number of weeks
y is calculated using
y = Base Amount + Additional * weeks
y = 10 + 5 * x
y = 10 + 5x
Next, it to plot the graph.
Take x = 0
y = 10 + 5 * 0
y = 10 + 0
y = 10
Take x = 3
y = 10 + 5 * 3
y = 10 + 15
y = 25
So, the graph must pass through
(0,10) and (3,25)
See attachment for graph.
The equation is y = 10 + 5x
Given that,
Anya started her savings with $10 and is saving $5 per week.Let y represent the total amount Anya has saved and x represent the number of weeks Calculation:y = Base Amount + Additional ( weeks)
y = 10 + 5 (x)
y = 10 + 5x
learn more about the equation here: https://brainly.com/question/10821476
Maggie has a 2-gallon pitcher of lemonade. How many liters of lemonade did she make?
I'LL GIVE BRAINLIEST!
Answer:
2 gallons converted to liters is 7.57 or 8 liters rounded
In a survey of 2,100 people owned a certain type of car, 1365 said they would by that type of car again. What percent of the people surveyed were satisfied with the car?
Answer:
65%
Step-by-step explanation:
Percentage = 1365/2100 *100
= 65%
what is the equation of the line through the origin and (3, 4)?
Answer:
y=3x+4
Step-by-step explanation:
Hope this works
If pand q vary inversely and pis 28 when Q is 29. determine q when p is equal to 14.
9514 1404 393
Answer:
q = 58
Step-by-step explanation:
If the variation is inverse, when p is multiplied by 1/2, q will be multiplied by the inverse (reciprocal) of 1/2, which is 2/1 = 2.
When p = (1/2)(28), q = (2)(29) = 59
q = 58
y+7=4/3(x+3)
A point on this line that is apparent from the given equation is?
Answer:
(-3, -7)
General Formulas and Concepts:
Algebra I
Point-Slope Form: y - y₁ = m(x - x₁)
x₁ - x coordinate y₁ - y coordinate m - slopeStep-by-step explanation:
Step 1: Define
Point-Slope Form: y + 7 = 4/3(x + 3)
Step 2: Break function
Slope m = 4/3
Point (-3, -7)
Find the measure of ULE in the triangle below.
Answer:
U = 71 L=60
Step-by-step explanation:
You subtract 180 from 109 to get the measure of U and then you add measure U and E to get 120. Then, you subtract 180 from 120 to get measure L.
Please help!!! I need to know the answer to this question quickly please
Which year group is this question from?
PLZZZZZZZZZZZZZZZZZZZZZZZZZZZ HELP ME!!!!!!!I BEGGING YOUUUUUUUU
Solve each equation for the variable. Show every step in your work
1. 2(x+12)=20
2. -4x-2=10
Answer:
Answers are below :)
Step-by-step explanation:
Q1- Divide both sides by 2
x +12 = 20/2
Simplify 20/2 to 10
x + 12 =10
Subtract 12 from both sides
x = 10 - 12
Simplify 10 - 12 to -2
x = -2
Q2. Add 2 to both sides
-4x = 10 + 2
Simplify 10 + 2 to 12
-4x=12
Divide both sides by -4
x = -12/4
Simplify 12/4 to 3
x = -3
Answer:
1. x=-2
2. X=-3
Step-by-step explanation:
1. 2(X+12)
2x+24=20
2x= -4
x= -2
2. -4x-2=10
-4x=12
x=-3
Raul earned $3,600 in one month. He paid $828 in income tax that month. What decimal represents the income tax rate?
Answer:
0.23
Step-by-step explanation:
A formula I like to use to find the answer to these types of questions is
[tex]\frac{828}{3600} =\frac{x}{100}[/tex]
first, multiply 828×100=82,800
now divide 82800÷3600=23
so your answer is 23%=[tex]\frac{23}{100}[/tex]=0.23
Help me out please I beg you
Answer:
tesrdxtcfygvoubucewh cwcs wuehcbwch w
Step-by-step explanation:
w edch dwjbsxchwej chwxc
Three times a number is at most negative six.
3x5-6
O 3x2-6
O 3x<-6
O 3x>-6
Answer:
3x ≤ - 6
Step-by-step explanation:
let the number be x.
three times of it would be 3x
since 3x is at most -6, 3x must be less than or equal to -6.
hence, 3x ≤ -6
however, your option seems to not have any sign that has equal to so perhaps the nearest answer would be 3x < -6
Which angles are alternate interior angles explain
Answer:
The answer is D.
Step-by-step explanation:
hope that helps
(7w - 6) +5 (-2.4w + 1)
Answer: The answer would be -5w-1
Step-by-step explanation:
Answer:
xcgvb vgjbnnnnnnnnnn vbjn bvh
Step-by-step explanation: