Answer:
We reject H₀, we find that the current level of mercury uptake in the Everglades has decrease
Step-by-step explanation:
We need to test the current wading bird average 14,6 vs the 1995 average. As sample mean is 14,6 and population mean is 15 we are going to check test is of one tail (left tail test)
Test Hypothesis:
Null hypothesis H₀ μ = μ₀
Alternative hypothesis Hₐ μ < μ₀
Sample size 25 then n < 30 we will use t-student table
Population mean : μ₀ = 15 ppm
sample mean : μ = 14,6 ppm
sample standard deviation: s = 1 ppm
Sample size n : 25
degrees of freedom df = n - 1 df = 24
We will develop the test for CI 90% then α = 10% α = 0,1 α/2 = 0,05
For that values in t student table we find:
t(c) = 1,711 by symmetry t(c) = - 1,711
To compute ts
t(s) = ( μ - μ₀ ) / s/√n
t(s) = 14,6 - 15 / 1 /√25
t(s) = - 0,4*5 / 1
t(s) = - 2
Comparing t(c)and t(s)
|t(s)| > |t(c) | and t(s) < t(c) -2 < -1,711
Therefore t(s) in in the rejection region, we reject H₀
the half life of c14 is 5730 years. Suppose that wood found at an archeological excavation site contains about 35% as much C14 as does living plant material. Determine when the wood was cut
Answer:
The wood was cut approximately 8679 years ago.
Step-by-step explanation:
At first we assume that examination occured in 2020. The decay of radioactive isotopes are represented by the following ordinary differential equation:
[tex]\frac{dm}{dt} = -\frac{m}{\tau}[/tex] (Eq. 1)
Where:
[tex]\frac{dm}{dt}[/tex] - First derivative of mass in time, measured in miligrams per year.
[tex]\tau[/tex] - Time constant, measured in years.
[tex]m[/tex] - Mass of the radioactive isotope, measured in miligrams.
Now we obtain the solution of this differential equation:
[tex]\int {\frac{dm}{m} } = -\frac{1}{\tau}\int dt[/tex]
[tex]\ln m = -\frac{1}{\tau} + C[/tex]
[tex]m(t) = m_{o}\cdot e^{-\frac{t}{\tau} }[/tex] (Eq. 2)
Where:
[tex]m_{o}[/tex] - Initial mass of isotope, measured in miligrams.
[tex]t[/tex] - Time, measured in years.
And time is cleared within the equation:
[tex]t = -\tau \cdot \ln \left[\frac{m(t)}{m_{o}} \right][/tex]
Then, time constant can be found as a function of half-life:
[tex]\tau = \frac{t_{1/2}}{\ln 2}[/tex] (Eq. 3)
If we know that [tex]t_{1/2} = 5730\,yr[/tex] and [tex]\frac{m(t)}{m_{o}} = 0.35[/tex], then:
[tex]\tau = \frac{5730\,yr}{\ln 2}[/tex]
[tex]\tau \approx 8266.643\,yr[/tex]
[tex]t = -(8266.643\,yr)\cdot \ln 0.35[/tex]
[tex]t \approx 8678.505\,yr[/tex]
The wood was cut approximately 8679 years ago.
X+ 2 = 5 and y-3 = 2
Answer:
x=3
y=5
because 5-2=3 so 3 is x
and 2+3 is 5 so y is 5
Answer:
X = 3, Y =
Step-by-step explanation:
This is because 2+3=5,
and5-3=2
Simplify (-4/5)divided by (3/-2). -8/15 -6/5 6/5 8/15
Answer:
8/15
Step-by-step explanation:
-4/5 ÷ -3/2
Copy dot flip
-4/5 * -2/3
Multiply the numerators
8
Multiply the denominators
15
Put the numerator over the denominator
8/15
Answer: 8/15
Step-by-step explanation: (-4/5)divided by (3/-2) is 8/15.
Blood pressure: High blood pressure has been identified as a risk factor for heart attacks and strokes. The proportion of U.S. adults with high blood pressure is 0.4. A sample of 39 U.S. adults is chosen. Use the TI-84 Plus Calculator as needed. Round the answer to at least four decimal places. Part: 0 / 60 of 6 Parts Complete Part 1 of 6 Is it appropriate to use the normal approximation to find the probability that more than 43% of the people in the sample have high blood pressure? It ▼(Choose one) appropriate to use the normal curve, since =np ▼(Choose one)10 and =n−1p ▼(Choose one) 10.
Answer:
Yes it appropriate to use the normal approximation to find the probability that more than 43% of the people in the sample have high blood pressure
Step-by-step explanation:
From the question we are told that
The population proportion is p=0.4
The sample size is n = 39
The sample proportion is [tex]\^ p = 0.43[/tex]
Generally for normal approximation to be used
[tex]np > 10[/tex]
so np = 39 * 0.4 = 15.6 > 10
and [tex]n(1- p) > 10[/tex]
so n(1-p ) = 39(1-0.4) = 23.4 >10
Given that the both condition is meet it mean that it appropriate to use the normal approximation to find the probability that more than 43% of the people in the sample have high blood pressure
what is 8 times 0.9 equal
Answer:
7.2
Step-by-step explanation:
anyone in flvs? we should find each other in live lessons lol
Answer:
nope
Step-by-step explanation:
You are given $893 in one, five, and ten dollar bills. There are 165 bills. There are twice as many five dollar bills as there are ones and tens combined. How many bills of each type are there?
Given:
You are given $893 in one, five, and ten dollar bills.
There are 165 bills.
There are twice as many five dollar bills as there are ones and tens combined.
To find:
How many bills of each type are there?
Solution:
Consider the number of bills of one dollars, five dollars and ten dollars are x, y and z respectively.
According to the question,
Number of bills : [tex]x+y+z=165[/tex] ...(1)
Total amount : [tex]1x+5y+10z=893[/tex] ...(2)
Condition : [tex]y=2(x+z)[/tex] ...(3)
Equation (3) can be written as
[tex]\dfrac{y}{2}=x+z[/tex] ...(4)
Substituting [tex]x+z=\dfrac{y}{2}[/tex] in (1), we get
[tex]\dfrac{y}{2}+y=165[/tex]
[tex]\dfrac{3y}{2}=165[/tex]
[tex]3y=330[/tex]
[tex]y=110[/tex]
Substituting y=110 in (4), we get
[tex]x+z=\dfrac{165}{2}[/tex]
[tex]x+z=55[/tex]
[tex]x=55-z[/tex] ...(5)
Substituting y=110 and x=55-z in (2), we get
[tex](55-z)+5(110)+10z=893[/tex]
[tex]55-z+550+10z=893[/tex]
[tex]9z+605=893[/tex]
[tex]9z=893-605[/tex]
[tex]9z=288[/tex]
Dividing both sides by 9, we get
[tex]z=32[/tex]
Substituting z=32 in (5), we get
[tex]x=55-32[/tex]
[tex]x=23[/tex]
Therefore,
One dollar bills = 23
Five dollars bills= 110
Ten dollars bills = 32
Two people start walking at the same time in the same direction. One person walks at 8 mph and the other
person walks at 3 mph. In how many hours will they be 1.25 miles apart?
Answer:
0.25hoursStep-by-step explanation:
Data
speed v1=8mph
speed v2=3mph
distance= 1.25
time t=?
speed= distance/time
distance=speed*time
1.25=8*t-3*t
1.25=8t-3t
1.25=5t
t=1.25/5
t=0.25hours
In minutes it is 15min
If a roof has a pitch of 5 to 11, how high will the roof rise over a 33-foot run?
a.
3
C.
2
72 feet
1 feet
b. 15 feet
d.
20 feet
The answer is b. 15ft
7th grade math help me plzzzz
Answer:
a. -14
b. -13
c. -5
d. -3
e. -12
f. 0
Step-by-step explanation:
hope it helps
Answer:
A is -14.
B is -13
C is -5
D is -3
E is -12
F is 0
Step-by-step explanation:
A, B, E both numbers are negative so you just add them together and add a negative sign.
C would read 4-9
D 10-7 and add a - to the answer
F is 6-6
Which expression is the coefficient of the n term -1
Answer:
C. -2n² - n + 5
Step-by-step explanation:
In expression C, the coefficient of the n term is -1;
The expression in choice C is given as:
-2n² - n + 5
The coefficient is the number before a variable;
For n², the coefficient is -2
for n, the coefficient is -1
SOMEONE PLEASE HELP ILL GIVE BRAINLIEST
Answer:
A.
Step-by-step explanation:
Write an equation in the line in slope intercept form
Answer:
Y=2x-1
Step-by-step explanation:
In order to find the slope, its rise over run. So you would move from (0,-1) to the next point it intercepts, (1,1) and find it from there
As for the Y-Intercept, it would just be wherever the line connects with the Y axis, which happens to be (0,-1) or Negative 1.
Calculate.
(2x105)(4.3x109)
Write your answer in scientific notation.
Answer:
9.8427x10⁴
Step-by-step explanation:
Answer:
98427x^2
9.8427x10^4
Step-by-step explanation:
Need help i will mark you brainliest
If b^2 = 25 then b= Answer it please
Answer:
b = 5
mark me as brainliest plz!! :DD
What number must be added to 101 to produce a number equal to the product of 101 x 21
Answer:
2020
Step-by-step explanation:
101 • 21 = 2121
2121 - 101 = 2020
w(t) = 3t – 1; t = 5
When five times a number is decreased by 9, the result is 11. What is the number?
Answer
4
Step-by-step explanation:
Add 9 to 11, then divide that by 5.
Answer:
4
Step-by-step explanation:
work backwards 11+9 is 20. Divide 20 by 5 = 4
rewrite the equation 10=1,000 with an exponet that makes it true .
Answer:
[tex]10^3=1,000[/tex]
Step-by-step explanation:
The expression 10=1,000 is obviously false, but we can make it true by rewriting it with an exponent.
Note that 1,000=10*10*10
Or, equivalently:
[tex]1,000=10^3[/tex]
Thus, if we modify the original false expression and add an exponent 3 to the base 10, then it would be true:
Original:
10=1,000 => false
Rewritten true:
[tex]\boxed{10^3=1,000}[/tex]
Michael exercises more than 35 minutes per day.
Use t to represent Michael's amount of exercise (in minutes per day).
Answer:
t>35
Step-by-step explanation:
Since Michael exercises more than 35 days, t is greater than 35. To express that in an inequality, the answer is t>35. Hope this helped!
8 tomatoes for $2 unit rate
I don't have much so please 17
Help ill give brainliest
Lily begins solving the equation 4(x – 1) – x = 3(x + 5) – 11. Her work is shown below.
4(x – 1) – x = 3(x + 5) – 11
4x – 4 – x = 3x + 15 – 11
3x – 4 = 3x + 4
How can her partial solution be interpreted?
A. The equation has one solution: x = 0.
B. The equation has one solution: x = 8.
C. The equation has no solution.
D. The equation has infinite solutions.
Answer:
C. no solution
Step-by-step explanation:
3x – 4 = 3x + 4
3x-3x=4+4
0=8
which is not possible.
So, it has no solutions.
Perform the indicated operation
3/4 divided by 1/3
Answer:
2 1/4
Step-by-step explanation:
3/4 ÷ 1/3 = ?
(to divide fractions faster you flip the second fraction so:)
3/4 x 3/1 = 2 1/4
I need help nowwwwww !!!!!????
you should just have to times the yards by three like the second one is 12
Number 10 plzz???????
In a certain state's lottery, 45 balls numbered 1 through 45 are placed in a machine and eight of them are drawn at random. If the eight numbers drawn match the numbers that a player had chosen, the player wins $1,000,000. In this lottery, the order in which the numbers are drawn does not matter.
Compute the probability that you win the million-dollar prize if you purchase a single lottery ticket. Write your answer as a reduced fraction.
P
(win) =
A single lottery ticket costs $2. Compute the Expected Value, to the state, if 10,000 lottery tickets are sold. Round your answer to the nearest dollar.
Answer: $
A single lottery ticket costs $2. Compute the Expected Value, to you, if you purchase 10,000 lottery tickets. Round your answer to the nearest dollar.
Answer: $
Step-by-step explanation:
The order of the numbers doesn't matter, so we'll use combinations instead of permutations. The number of combinations is:
₄₅C₈ = 215,553,195
So the probability of a ticket having the winning combination is 1 / 215,553,195.
The expected value to the state is:
E(X) = 10,000 (1) ($2) + 10,000 (1 / 215,553,195) (-$1,000,000)
E(X) = $19954
The expected value to you is:
E(X) = 10,000 (1) (-$2) + 10,000 (1 / 215,553,195) ($1,000,000)
E(X) = -$19954
Your teacher invented another game: You will pick one card from a deck of cards. If
you pick a heart, you will win $25.00. Otherwise, you will lose $5.00.
From the standpoint of the player, what is the expected value of this game?
Enter expected value
What does the expected value tell us about the game?
O The game is good to play, you will make money on average.
O The game is NOT good to play, you will tend to lose money.
O It doesn't matter if you play, you will generally break even.
Answer:
C
Step-by-step explanation:
QUICK
solve this equation
a^n+b^n=
Whats 27.16 - 3.1 x 1.4 evaluated?
PLEASE HELP
Answer:
22.82
Step-by-step explanation:
can u plz mark me as brainliest??
Answer:
22.82
Step-by-step explanation:
3.1*1.4 = 4.34
27.16-4.34 = 22.82
[edited, I messed up the order of operations before, sorry]