Total cost of the pencils is the number of pencils x the price per pencil:
4 x 0.30 = $1.20
Now add what you got back for change:
1.20 + 0.80 = 2.00
You gave the cashier $2.00
what is a case control study
Answer:
A study that compares two groups of people: those with the disease or condition under study (cases) and a very similar group of people who do not have the disease or condition (controls). Researchers study the medical and lifestyle histories of the people in each group to learn what factors may be associated with the disease or condition. For example, one group may have been exposed to a particular substance that the other was not. Also called retrospective study.
Step-by-step explanation:
Answer:
A case-control study is designed to help determine if an exposure is associated with an outcome (i.e., disease or condition of interest).
Step-by-step explanation:
The measures of the angles of the triangle are 32°, 53º,
950. Based on the side lengths, what are the measures
of each angle?
m2A = 95°, mZB = 53º, mZC = 32°
MZA= 32º, mzB = 53º, mZC = 95°
MZA= 43º, mZB = 32°, m2C = 95°
OmZA= 53º, m B = 95°, m2C = 32°
Answer:
m∠A = 32°
Step-by-step explanation:
8^2 = 12^2 + 15^2 - 2*12*15*cosA
Answer:
B
Step-by-step explanation:
did it on edge
Imara used these steps to find the length of the hypotenuse of the right triangle.
3 squares are positioned to form a right triangle. The small square is labeled 15, medium square is 20, and large square is not labeled.
Step 1: Find the area of the square with side lengths of 20: 400
Step 2: Find the area of the square with side lengths of 15: 225
Step 3: Find the sum of the areas of the two squares: 625
Step 4: State the length of the hypotenuse: 625
Answer:
C, "She could have found the sum of 15 and 20 and then squared the sum."
Step-by-step explanation:
I just took the test on Edge :)
The answer is C, I got it right on edge.
Have a nice day everyone <3.
The sound pressure P for a given sound is given by:
P= 10 log W/ Wo
Its units are decibels (dB). W is the size of a variable energy source (called the sound power), measured in Watts. Wo is the lowest threshold of sound that humans can typically hear. It is a constant given by:
Wo=10^-12 W/m2
a) Find the rate of change of the sound pressure P with respect to time if W=7.2 and dW/dt = 0.5 at some given time t.
b) If the variable sound power W is given by W = t2 +t +1, find the rate of change of the sound pressure P, at time t = 3s.
c) If W = cos 0.2t, find the rate of change of the sound pressure P, at time t = 15 (calculators in radians)
Answer:
a. 0.302 dB/s
b. 2.34 dB/s
c. 1.24 dB/s
Step-by-step explanation:
a) Find the rate of change of the sound pressure P with respect to time if W=7.2 and dW/dt = 0.5 at some given time t.
Since P = 10log(W/W₀), its rate of change with respect to time is
dP/dt = dP/dW × dW/dt
dP/dW = d[10logW - 10logW₀]/dt
dP/dW = d[10lnW/2.303 - 10logW₀]/dt
= 10/2.303W - 0
= 10/(2.303W)
dP/dt = dP/dW × dW/dt
dP/dt = 10/(2.303W) × dW/dt
Since dW/dt = 0.5 when W = 7.2, then
dP/dt = 10/(2.303 × 7.2) × 0.5
dP/dt = 10/16.5816 × 0.5
dP/dt = 0.603 × 0.5
dP/dt = 0.302 dB/s
b) If the variable sound power W is given by W = t² + t + 1, find the rate of change of the sound pressure P, at time t = 3s.
Since P = 10log(W/W₀), its rate of change with respect to time is
dP/dt = dP/dW × dW/dt
dP/dW = d[10logW - 10logW₀]/dt
dP/dW = d[10lnW/2.303 - 10logW₀]/dt
= 10/2.303W - 0
= 10/(2.303W)
and dW/dt = d(t² + t + 1)/dt = 2t + 1
So, dP/dt = dP/dW × dW/dt
dP/dt = 10/(2.303W) × (2t + 1)
dP/dt = 10(2t + 1)/(2.303W)
dP/dt = 10(2t + 1)/[2.303(t² + t + 1)]
we then substitute t = 3 into the equation
dP/dt = 10(2t + 1)/[2.303(t² + t + 1)]
dP/dt = 10(2(3) + 1)/[2.303((3)² + 3 + 1)]
dP/dt = 10(6 + 1)/[2.303(9 + 3 + 1)]
dP/dt = 10(7)/[2.303(13)]
dP/dt = 70/29.939
dP/dt = 2.34 dB/s
c) If W = cos 0.2t, find the rate of change of the sound pressure P, at time t = 15 (calculators in radians)
Since dP/dt = dP/dW × dW/dt and dP/dW = 10/(2.303W) and W = cos(0.2t), dW/dt = -0.2sin(0.2t)
So, dP/dt = dP/dW × dW/dt
dP/dt = 10/(2.303W) × -0.2sin(0.2t)
dP/dt = -20sin(0.2t)/(2.303W)
dP/dt = -20sin(0.2t)/(2.303cos(0.2t))
dP/dt = -20tan(0.2t)/2.303
when t = 15, we have
dP/dt = -20tan(0.2 × 15)/2.303
dP/dt = -20tan3/2.303
dP/dt = -20 × -0.1425/2.303
dP/dt = 2.8509/2.303
dP/dt = 1.238
dP/dt ≅ 1.24 dB/s
A rectangle has vertices (−5, 6), (−1, 6), (−1, 3), and (−5, 3). It is first dilated by the rule (x, y)→(7x, 7y) and then translated 10 units down. What are the coordinates of the image?
A(−35, 32), (−7, 32), (−7, 11), (−35, 11)
B(−45, 42), (−17, 42), (−17, 21), (−45, 21)
C(−105, 42), (−77, 42), (−77, 21), (−105, 21)
D(−35,−28), (−7,−28), (−7,−49), (−35,−49)
Dina invests $600 for 5 years at a rate of 2% per year compound interest.
Calculate the value of this investment at the end of the 5 years.
Answer:
The value of this investment at the end of the 5 years is of $662.5.
Step-by-step explanation:
Compound interest:
The compound interest formula is given by:
[tex]A(t) = P(1 + \frac{r}{n})^{nt}[/tex]
Where A(t) is the amount of money after t years, P is the principal(the initial sum of money), r is the interest rate(as a decimal value), n is the number of times that interest is compounded per year and t is the time in years for which the money is invested or borrowed.
Dina invests $600 for 5 years at a rate of 2% per year compound interest.
This means that [tex]P = 600, t = 5, r = 0.02, n = 1[/tex]. Thus
[tex]A(t) = P(1 + \frac{r}{n})^{nt}[/tex]
[tex]A(t) = 600(1 + \frac{0.02}{1})^{t}[/tex]
[tex]A(t) = 600(1.02)^t[/tex]
Calculate the value of this investment at the end of the 5 years.
This is A(5). So
[tex]A(5) = 600(1.02)^5 = 662.5[/tex]
The value of this investment at the end of the 5 years is of $662.5.
Juan y rosa van a repartirse un pastel por partes iguales sin que sobre nada .Si de la fiesta sobró 3/4pastel .¿cuanto le tocó a cada uno?
Usando el método de polya:
a. Que se pregunta?
la fracción de cuánto obtendría cada uno de ellos y compartiría por igual.b. ¿Cuáles son los datos dados?
¾ tarta, 2 personas (Juan y Rosa)c. ¿Cuál es la operación que se utilizará?
divisiónd. oración numérica:
¾ ÷ 2e. Solución y respuesta completa:
[tex] \frac{3}{4} \div 2 \\ = \frac{3}{4} \times \frac{1}{2} \\ = \frac{3}{8} [/tex]
explicación paso a paso:
Multiplica por el recíproco: Dividir es equivalente a multiplicar por el recíproco.Multiplicar: multiplica las fraccionesForma decimal: 0.375
☆彡Hanna#CarryOnLearning
Solve for x. Round to the nearest hundredth.
A. 0.02
B. 25.17
C. 0.03
B. 12.27
Work Shown:
cos(angle) = adjacent/hypotenuse
cos(64) = x/28
x/28 = cos(64)
x = 28*cos(64)
x = 12.2743921100941
x = 12.27
Hai vòi nước cùng chảy vào một bể. Vòi thứ nhất chảy trong 8 giờ thì đầy bể, vòi thứ hai chảy trong vòng 10 giờ thì đầy bể. Hỏi:
a, cả hai vòi cùng chảy thì sau bao lâu sẽ đầy bể
b, Nếu có một một vòi thứ ba Thảo nước ra trong 16 giờ thì sẽ cạn hết bể đầy nước thì khi mở cả 3 vòi cùng một lúc sau bao nhiêu lâu sẽ đầy bể(lúc đầu bể đầy nước)
Answer:
Please say in English
Step-by-step explanation:
I don't understand, Sorry
From 22 potential women jurors and 25 potential men jurors, a jury of 12 is chosen at random. Let X be the number of women selected. Find the probability mass function of X.
Answer:
The probability mass function is:
[tex]P(X = x) = h(x,47,12,22) = \frac{C_{22,x}*C_{25,12-x}}{C_{47,12}}[/tex]
Step-by-step explanation:
The people are chosen without replacement, which means that the hypergeometric distribution is used to solve this question.
Hypergeometric distribution:
The probability mass of the hypergeometric probability distribution is given by:
[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}[/tex]
In which:
x is the number of successes.
N is the size of the population.
n is the size of the sample.
k is the total number of desired outcomes.
In this question:
22 + 25 = 47 jurors, so [tex]N = 47[/tex]
22 are women, which means that [tex]k = 22[/tex]
Jury of 12, which means that [tex]n = 12[/tex].
Thus
[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}[/tex]
[tex]P(X = x) = h(x,47,12,22) = \frac{C_{22,x}*C_{25,12-x}}{C_{47,12}}[/tex]
Which is the probability mass function.
In one hour Dele walks 8km. How
long will it take her to walk 14km at
the same rate?
Answer:
1.45 h
Step-by-step explanation:
common factor of 8 and 14 is 2.
every 2km dele takes 15 minutes.
we know this because 15 minutes is 1/4 of an hour and 2km is 1/4 of 8km
14km/2km = 7
7*15 minutes = 1.45 hours
Answer:
1.75 hours/ 1hr 45 min
Step-by-step explanation:
1hr = 8 Km
?? = 14 Km
= (14km × 1hr)/ ( 8km)
= 1.75hours
= 1hr 45min
Which expression is equivalent to (6x2 + 4)(x + 5) ?
A 6x2 + 20
B 6x2 + 16x + 20
C 603 + 30x2 + 4x + 20
D) 6x3 + 11x2 + 3x + 20
Answer: [tex]6x^3 +30x^2 +4x+20[/tex]
Step-by-step explanation:
[tex](6x^2 +4)(x+5)\\\\ =6x^3 +30x^2 +4x+20[/tex]
reduce 5/10 to it's smallest fraction
Answer:
1/2
If you divide both numbers by 5, you would get 1/2
help please show work
Becky's statistics teacher was teaching the class how to perform the z-test for a proportion. Becky was bored because she had already mastered the test, so she decided to see if the coin she had in her pocket would come up heads or tails in a truly random fashion when flipped. She discretely flipped the coin 30 times and got heads 18 times. Becky conducts a one-proportion hypothesis test at the 5% significance level, to test whether the true proportion of heads is different from 50%. Which answer choice shows the correct null and alternative hypotheses for this test?
Answer:
H0 : p = 0.5
H1 : p ≠ 0.5
Two tailed test
Step-by-step explanation:
The test if the true proportion of heads is different from 50%; this means the initial truth, that is the true proportion is 50% ; which is the null ;
H0 : p = 0.5
The researcher intends to test if the true proportion is not 50% ; that is the researcher is n spwcudfic about if the proportion is lower or higher, he just wants to test that the proportion is different, hence the test could go either way ;
Alternative hypothesis ;
H1 : p ≠ 0.5
Since the sign in the alternative hypothesis could be in either direction, then we have a two tailed test
Graph the image of trapezoid PQRS after a translation 9 units right and 10 units up.
Passion wants to rent a car to take a trip and has a budget of $75. There is a fixed rental fee of $25 and a daily fee of $10. Write ab inequality that would be used to solve for the maximum number of days for which passion can rent the car on her budget
Answer:
5 days
Step-by-step explanation:
75 = 10d +25
-25 -25
50 = 10d
/ /
10 10
5 = d
What is the formula of a palindrome?
Answer:
For example, 6(1001) + 3(110) = 6006 + 330 = 6336 is a palindrome. Since 11 is a factor of both 1001 and 110, we conclude that all four digit palindromes are divisible by 11.
ques
mid vallue frequency
5. 5
10. 20
15. 10
20. 55
25. 22
30. 29
find mode from the following
Answer:
the mode is 20
it has the highest frequency
Photo attached!!!!!!!
Answer:
i cant see the photo
Step-by-step explanation:
Any help? Algebra I
9514 1404 393
Answer:
2p +3d = 18.25; 4p +2d = 27.50popcorn: $5.75; drink: $2.25Step-by-step explanation:
a) Let p and d represent the prices of a bag of popcorn and a drink, respectively.
Mohamed's purchase is ...
2p +3d = 18.25
Miguel's purchase is ...
4p +2d = 27.50
__
b) We can subtract half the second equation from the first to get an equation for the cost of a drink.
(2p +3d) -1/2(4p +2d) = (18.25) -1/2(27.50)
2d = 4.50 . . . . . . simplify
d = 2.25 . . . . . . divide by 2
4p +2(2.25) = 27.50 . . . . substitute for d in the second equation
4p = 23.00 . . . . . . . . . subtract 4.50
p = 5.75 . . . . . . . . . divide by 4
The cost of a bag of popcorn is $5.75; the cost of a drink is $2.25.
Please help is for now :(
Answer:
d
Step-by-step explanation:
d part it is. this is the answer
I’ve been stuck on this problem I can’t seem to get 7 9/4 into the ABC form
Answer:
7 square root 9^4
Step-by-step explanation:
Find the Value of x
Answer:
42
Step-by-step explanation:
(adjacent straight angles sum up to 180)
3x+54=180
x=42
Which of the following represents the factorization of the trinomial below?
X2 - 2x - 48
ANSWER ASAP
Answer:
(X+6)(x-8)
Step-by-step explanation:
Answer:
(x-8)(x+6)
Step-by-step explanation:
Factor the trinomial using the AC method.
x * x = x^2
-8 + 6 = -2
-8 * 6 = -48
ok and again i just dont understand well so this is why i am asking so many times and u guys and girls are getting alot of points
Answer:
The answer is A
Step-by-step explanation:
These marbles are placed in a bag and two
of them are randomly drawn.
What is the probability of drawing two pink
marbles if the first one is placed back in the
bag before the second draw?
Give your answer as a ratio, reduced to
simplest terms.
[?]
Hint: Multiply the probability of the 1st Event by the
probability of the 2nd Event to get your answer.
Enter
========================================================
Explanation:
There are 3 pink marbles out of 10 total (we can see that 2 yellow + 3 pink + 5 blue = 10 total)
The fraction 3/10 represents the probability of pulling out a pink marble at random. Since the first one is put back, this means the fraction 3/10 stays the same on the second draw as well.
We use the idea mentioned in the hint to multiply the fractions:
(3/10)*(3/10) = (3*3)/(10*10) = 9/100
The probability of pulling two pink marbles in a row is 9/100, where the first marble is put back.
Effectively, if you were given 100 tries at doing this, you should expect about 9 of those times you get 2 pink marbles in a row.
A 15-day supply of vitamins costs $1.74, what is the price in cents per day?
Answer:
it costs 12 cents per day.
Step-by-step explanation:
15 days cost $1.74
1 day then costs 1.74/15 = $0.116 ≈ $0.12
hi how are you? will you kindly help me with this only one?
Answer:
The answer is J.
Step-by-step explanation:
what is the value of x?
Answer:
46
ayo how r u doin siahsvsgshsgsgsgsg
