Answer:
[tex]Outcomes = \{HHHH, HHHT,TTTH, TTTT\}[/tex]
Step-by-step explanation:
Given
[tex]S = \{HHHH, HHHT, HHTH, HHTT,HTHH, HTHT, HTTH, HTTT, THHH, THHT,[/tex]
[tex]THTH, THTT,TTHH, TTHT, TTTH, TTTT\}[/tex]
Required
The outcomes where the first three tosses are the same
To do this, we list out the outcomes that the first three are HHH or TTT.
So, we have:
[tex]Outcomes = \{HHHH, HHHT,TTTH, TTTT\}[/tex]
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
Ivan is saving money to buy a game. So far he has saved 8, which is one-fourth of the total cost of the game. How much does the game cost?
Answer:
[tex]\$32[/tex]
Step-by-step explanation:
Let the cost of the game be [tex]x[/tex]. Since one-fourth of the cost of the game is equal to 8 dollars, we have the following equation:
[tex]\frac{1}{4}x=8[/tex]
Multiply both sides by 4 to isolate and solve for [tex]x[/tex]:
[tex]x=8\cdot 4=\boxed{\$32}[/tex]
help please show work
Find the Value of x
Answer:
42
Step-by-step explanation:
(adjacent straight angles sum up to 180)
3x+54=180
x=42
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
Please help is for now :(
Answer:
d
Step-by-step explanation:
d part it is. this is the answer
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.
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.
Help please!!!!! I don't really get this, help asap.
Answer:
7 boxes
Step-by-step explanation:
We can use ratios to solve
12 bars 42 bars
---------- = ---------------
2 boxes x boxes
Using cross products
12x = 2 *42
12x = 84
Divide by 12
12x/12 = 84/12
x = 7
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.
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.
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:
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:
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
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
please helpppp!!! it’s timed!!!! thank u for helping!!!!!
Answer:
10π in.
Step-by-step explanation:
circumference of a circle = 2πr
=2*π*5
=10π in.
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
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.
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
An aerodynamic 1,000 kg car takes about 270 newtons of force to maintain a speed of 25 m/s. how much horsepower is required from the engine to maintain this speed?
Answer:
9.05 horse power
Step-by-step explanation:
Given:
Force = 270 Newton
Speed = 25 m/s
Power = Force * velocity
Power = 270 Newton * 25 m/s
Power = 6750 watt
Recall:
1 horse power = 746 watts
Hence, required horsepower is :
6750 watt / 746 watt
9.048 hp
9.05 horse power
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]
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
Can someone please help please.you will get 48 points
Answer:
x = 20
Step-by-step explanation:
We can use a ratio to solve
10 14
------ = ----------
x 28
Using cross products
10 * 28 = 14*x
280 = 14x
Divide by 14
280/14 = 14x/14
20 =x
Answer:
20 cm
Step-by-step explanation:
It says that both of these shapes are similar. If we divide 28/14=2.
Then we can also multiply 10 cm by 2 cm to get 20 cm .
x= 20 cm
Hope this helps!
reduce 5/10 to it's smallest fraction
Answer:
1/2
If you divide both numbers by 5, you would get 1/2
what is the value of x?
Answer:
46
ayo how r u doin siahsvsgshsgsgsgsg
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.
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:
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)
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
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
