Answer:
The smallest sample size that will produce an interval with these specifications is 601.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].
The margin of error is:
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
95% confidence level
So [tex]\alpha = 0.05[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].
He would like you to report a 95% confidence interval with a margin of error no more than 0.04. What is the smallest sample size that will produce an interval with these specifications?
We have to find n for which M = 0.04.
We dont know the true proportion, so we use [tex]\pi = 0.5[/tex], which is when the smallest sample size needed will have it's largest value.
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
[tex]0.04 = 1.96\sqrt{\frac{0.5*0.5}{n}}[/tex]
[tex]0.04\sqrt{n} = 1.96*0.5[/tex]
[tex]\sqrt{n} = \frac{1.96*0.5}{0.04}[/tex]
[tex](\sqrt{n})^2 = (\frac{1.96*0.5}{0.04})^2[/tex]
[tex]n = 600.25[/tex]
Rounding up
The smallest sample size that will produce an interval with these specifications is 601.
A new car battery is sold with a two-year warranty whereby the owner gets the battery replaced free of cost if it breaks down during the warranty period. Suppose an auto store makes a net profit of $20 on batteries that stay trouble-free during the warranty period; it makes a net loss of $10 on batteries that break down. The life of batteries is known to be normally distributed with a mean and a standard deviation of 40 and 16 months, respectively.
Required:
a. What is the probability that a battery will break down during the warranty period?
b. What is the expected profit of the auto store on a battery?
c. What is the expected monthly profit on batteries if the auto store sells an average of 500 batteries a month?
Answer:
a) 0.1587 = 15.87% probability that a battery will break down during the warranty period.
b) The expected profit of the auto store on a battery is of $15.239.
c) The expected monthly profit on batteries if the auto store sells an average of 500 batteries a month is of $7,619.50.
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score 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 p-value, we get the probability that the value of the measure is greater than X.
The life of batteries is known to be normally distributed with a mean and a standard deviation of 40 and 16 months, respectively.
This means that [tex]\mu = 40, \sigma = 16[/tex]
a. What is the probability that a battery will break down during the warranty period?
Two year warranty, that is, 24 months. This probability is the pvalue of Z when X = 24. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{24 - 40}{16}[/tex]
[tex]Z = -1[/tex]
[tex]Z = -1[/tex] has a pvalue of 0.1587.
0.1587 = 15.87% probability that a battery will break down during the warranty period.
b. What is the expected profit of the auto store on a battery?
1 - 0.1587 = 0.8413 probability of a profit of $20.
0.1587 probability of a loss of $10. So
[tex]E = 0.8413*20 - 0.1587*10 = 15.239[/tex]
The expected profit of the auto store on a battery is of $15.239.
c. What is the expected monthly profit on batteries if the auto store sells an average of 500 batteries a month?
Multiplying the average for a battery by 500. So
15.239*500 = $7,619.50
The expected monthly profit on batteries if the auto store sells an average of 500 batteries a month is of $7,619.50.
Freddy swims at the community center each week. He wonders about the area of
the pool. He thinks he cannot figure it out because the pool is not rectangular. Can
you figure out the area of the swimming pool at Freddy's community center?
Answer:
Yes you can.
Step-by-step explanation:
Multiply length x width.
Other:
If you want me to find the exact answer, it is not currently possible as you haven't given me any dimensions.
Zach wants to paint the top of the table shown. What is the approximate area that he will paint? Use 3.14 for pi Round to the nearest whole number of inches.
Answer:
≈4776
Step-by-step explanation:
r=78/2
r=39
A=3.14r^2
A=3.14(39)^2
A=3.14*1521
A≈4776
Hope this helps :)
What do you need to do first to solve this equation? -62 +4= -20
Answer:
Add -62 and 4
Step-by-step explanation:
Step-by-step explanation:
-62+4=-20
-58=-20
58=20
Need help with full work quick
Answer:
Step-by-step explanation:
36x^3 - 81x
9x(4x^2 - 9)
9x(2x - 3)(2x + 3)
She is right
The Lemonade War is a book with 14 chapters. Each chapter
represents a
of the book. *
quarter
half
fraction
O third
solve each system by eliminating one of the variables by addition or
subtraction.
Answer:
1) x- y = 8
x + y = 12
eliminate one variable by adding the equations
2x = 20
divided by 2 on both sides
x = 10
substitute the value of x in the equation 1
10 - y = 8
-y = 8- 10
y =2
[x , y]
[10 , 2]
2) 2x - y = 4
3x + y = 6
eliminate one variable by adding the equations
5x = 10
x = 2
substitute the value of x in the equation
2(2) - y = 4
4 - y = 4
y = 0
[x ; y]
[2; 0]
3) x + 2y = 10
x + 4y = 14
multiply equation 1 by - 1
-x -2y = -10
x + 4y = 14
eliminate one variable by adding the equations
2 y = 4
y = 2
substitute the value of y in the equation 1
x + 2(2) = 10
x + 4 = 10
x = 6
[x ; y]
[6 ; 2]
4 ) 3x + y = 9
y = 3x + 6
simplify the expression
3x + y = 9
- 3x + y = 6
eliminate one variable by adding the equations
2y = 15
y = 15/2
substitute the value of y in equation 1
3x + 15/ 2 = 9
3x = 3/2
x = 1/2
[x ; y]
[1/2 ; 15/ 2]
5) 4x + 5y = 15
6x - 5y = 18
eliminate one variable by adding the equations
10 x = 33
× = 33/10
substitute the value of x in equation I
4 (33/10) + 5y = 15
66/5 + 5y =15
5y = 9/5
y = 9/25
[x ; y]
[33/10 ; 9/25]
6) 5x = 7y
x + 7y = 21
in equation I move the variable to the left
5x - 7y = 0
x + 7 y = 21
eliminate one variable by adding the equations
6x = 21
x = 7/2
substitute the value of x in the equation
5(7/2) = 7y
35/2 = 7y
5/2 = y
[x ; y ]
[7/2 ; 5/2 ]
Which of the following is the function representing the graph below?
a. f(x) = 4x
b. f(x) = 4x − 3
c. f(x) = 4x + 3
d. f(x) = 4(x + 3)
Answer:
d. f(x) = 4(x + 3)
Tyra's kitchen is 42 m wide and 6.3 m long. She is pasting a decorative border strip that costs $5.95 per meter around the top edge of all the walls. How much will she spend?
Answer:
$124.95Step-by-step explanation:
The length of the strip is equal to perimeter of the kitchen.
P = 2(4.2 + 6.3) = 21 mCost of the strip is:
21*$5.95 = $124.95At the beginning of January of the current year, Thomas Law Center's ledger reflected a normal balance of $55,000 for accounts receivable. During January, the company collected $17,800 from customers on account and provided additional services to customers on account totaling $14,000. Additionally, during January one customer paid Thomas $6,500 for services to be provided in the future. At the end of January, the balance in the accounts receivable account should be:
which of the following is equal to the rational expression?
Answer:
d
Step-by-step explanation:
please mark as brainliest if correct
thank you
have a great day/night
:)
pleaseeeeee help me out quickkk solve for x
Answer:
x = 27.2
Step-by-step explanation:
Apply trigonometric function to solve for x.
Reference angle = 54°
Side length opposite to reference angle = 22
Hypotenuse = x
We would apply SOH:
Sin 54 = Opp/Hyp
Sin 54 = 22/x
x*sin 54 = 22
x = 22/sin 54
x = 27.1934955 ≈ 27.2 (nearest tenth)
What is the area of the triangle?
Answer:
45
Step-by-step explanation:
9x10/2=45
Can someone please help me?
Answer:
D
Step-by-step explanation:
This is a pythagoream thereom question, the area of a square can be found by multiplying the sides. All the sides of a sqaure are the same so we are basically sqauring the side lengths. That is where the [tex]BE^{2}[/tex] and [tex]BH^{2}[/tex] come from. The problem tells us that the area of the two small squares are equal to the one bigger square. And the area of the bigger sqaure can be found by squaring that side EH. So [tex]BE^{2}[/tex]+[tex]BH^{2} =EH^{2}[/tex].
Solve the inequality. m/-5 < or = 4
Answer:
M < or = -20
Step-by-step explanation:
Brainlist please
Last one!!!hdbsjsbsjdsnsjsn
Answer:
Option c is correct
Step-by-step explanation:
Hope it helps✌
Answer:
9.4
3rd option
The boats are 9.4 units apart.
look at pic 10 pts will mark brainilest
Answer:
C) It will not change
Hope this helps! :)
. Duke's photography pays $9 for a 5x7 photograph.
If the photograph is sold for $15, what is the
percent of markup based on cost?
Answer:
the markup percentage is 66.67%
Step-by-step explanation:
The computation of the percent of markup based on cost is shown below:
= (Selling price - paid price) ÷ (paid price)
= ($15 - $9) ÷ ($9)
= 66.67%
By taking the difference of the selling price & paid price and then divided it by paid price we can get the percentage of markup
Hence, the markup percentage is 66.67%
Get this answer correct u get a brainleist
That is the volume of a basketball
if u look it up u dont get it
Answer:
Imma guess around 350 cubic inches
Step-by-step explanation:
I'm just going off of my hand compared to my basketball
Answer:
About 433.526 inches^3
Step-by-step explanation:
Goal: Calculate the volume of a Basketball as accurately as possible. Objective 1: Calculate the volume of a basketball.
Step One: Find the radius of the basket ball inflated at 8 PSI. To do this we used a string to measure the circumference of the basket ball arriving at a measurement of 29 inches. Next we inserted that number into the formula C = 2πR where C= circumference and R= Radius. We found that where C= 29inches, R= 4.615 inches.
Solve with Volume of a ball or sphere = 4/3*pi*radius
Plzzzz answer fast..
Answer:
A) Yes; AA Similarity
Step-by-step explanation:
Yes; AA Similarity
What is the surface area of the tent?
Answer:
i think the answer is 105.96
Given f (x) = x + 1 and g(x) = x2, what is (gof)(x)?
Answer:
(gof)(x) = x² + 2x + 1
Step-by-step explanation:
You can solve this by plugging f into g and finding the result:
(gof)(x) = f(x)²
= (x + 1)²
= x² + 2x + 1
Y=-4. Y=x-8 solve for substitution
Answer:
ok
Step-by-step explanation:
I think
A car travels 30 1/5 miles in 2/3 of an hour what is the average speed in miles per hour of the ca A car travels 30 1/5 miles in 2/3 of an hour what is the average speed in miles per hour of the car
Answer:
45.3 miles/h
Step-by-step explanation:
let 'x' be the speed of the car.
60 × 2/3 = 120/3 = 40
30 × 1/5 = 151/5
151/5 /40 = x / 60
151 / 200 = x / 60
=> x = (151×60) / 200
=> x = 45.3
(hope this helps can i plz have brainlist :D hehe)
Help please thanks!!!
Answer:
Four tenths
Step-by-step explanation:
You are correct. The dot is on 0.4. the 4 is in the tenths place, so four tenths.
Find the volume of the cylinder.
Answer:
160pi
Step-by-step explanation:
the volume of a cylinder is found using the formula V=pi x r² x h. taking r=4 this means we have pi x 16 x10 =160pi
Which of the following shows the correct first step to solve x^2-16x=-21 by completing the square? I'll give brainiest ASAP
`
An expression is defined as a set of numbers, variables, and mathematical operations. The correct option is C.
What is an Expression?In mathematics, an expression is defined as a set of numbers, variables, and mathematical operations formed according to rules dependent on the context.
The perfect square of the given expression can be created by adding 36 to the expression, then the expression will reduce to,
(x-6)² = x² - 12x + 36
Hence, the correct option is C.
Learn more about Expression:
https://brainly.com/question/13947055
#SPJ1
PLEASE HELP !! ILL GIVE BRAINLIEST !!
Answer:
∠GHJ and ∠FEC
Step-by-step explanation:
Alternate exterior angles are two angles that lie on the outer part of the parallel lines but on different sides.
∠GHJ and ∠FEC lie on the outer parts of the parallel lines, but different sides.
∠GHJ is on the lower left side.
∠FEC is on the upper right side.
Madison was given a large box of 48 chocolates for her birthday. If she eats exactly 5
chocolates each day, how many chocolates would Madison have remaining 5 days
after her birthday?
Answer:
The answer is 23 chocolates
Step-by-step explanation:
You do 5 times 5 for her eating 5 chocolates a day for 5 days to get 25 and then you take 48 and subtract it by 25 and you get 23
I need the value of Y
9514 1404 393
Answer:
y = 6
Step-by-step explanation:
Let's call the marked angles A, B, C, clockwise from upper left.
Along the vertical transversal, we observe that A+90° and C are alternate exterior angles, so are congruent. This lets us find a value for x.
A+90 = C
4x +90 = 11x -8
98 = 7x
14 = x
Then angle A is ...
A = 4x° = 4(14)° = 56°
__
Along the horizontal transversal, we observe that A and B are alternate exterior angles, so are congruent. This lets us find a value for y.
A = B
56° = (9y +2)°
54 = 9y
6 = y
The value of y is 6.