Answer:
Step-by-step explanation:
The decay rate of strontium-90 is -.0244 as given.
For b., we have to use the formula to find out how much is left after 30 years. This will be important for part d.
[tex]A(t)=400e^{-.0244(30)}[/tex] which simplifies a bit to
A(t) = 400(.4809461353) so
A(t) = 192.4 g
For c., we have to find out how long it takes for the initial amount of 400 g to decay to 100:
[tex]100=400e^{-.0244t}[/tex]. Begin by dividing both sides by 400:
[tex].25=e^{-.0244t[/tex] and then take the natural log of both sides:
[tex]ln(.25)=lne^{-.0244t[/tex] . The natural log and the e cancel each other out since they are inverses of one another, leaving us with:
ln(.25) = -.0244t and divide by -.0244:
61.8 years = t
For d., we figured in b that after 30 years, 192.4 g of the element was left, so we can use that to solve for the half-life in a different formula:
[tex]A(t)=A_0(.5)^{\frac{t}{H}[/tex] and we are solving for H. Filling in:
[tex]192.4=400(.5)^{\frac{30}{H}[/tex] and begin by dividing both sides by 400:
[tex].481=(.5)^{\frac{30}{H}[/tex] and take the natural log of both sides, which allows us to pull the exponent out front. I'm going to include that step in with this one:
ln(.481) = [tex]\frac{30}{H}[/tex] ln(.5) and then divide both sides by ln(.5):
[tex]\frac{ln(.481)}{ln(.5)}=\frac{30}{H}[/tex] and cross multiply and isolate the H to get:
[tex]H=\frac{30ln(.5)}{ln(.481)}[/tex] and
H = 28.4 years
Consider the line 9x + 8y = -8.
What is the slope of a line perpendicular to this line?
What is the slope of a line parallel to this line?
Answer:
Step-by-step explanation:
The slope of the line is -9/8. The slope of any parallel to the line is also -9/8.
8x + 2 = = 7 + 5x + 15
Answer:
2.5
Step-by-step explanation:
8x + 2 = 7 + 5x + 15
Combine like terms:
8x + 2 = 7 + 5x + 15
8x + 2 = 22
-2 -2
-----------------
8x = 20
---- ----
8 8
x = 2.5
Hope this helped.
A 40-foot tree casts a shadow 60 feet long. How long would the shadow of a 6-foot man be at that time?
Answer:
26 ft
Step-by-step explanation:
I'm guessing this is how it's done
60-40= 20
there for at this time any shadow would be 20x it's original height/length
so 6+20=26 ft
lmk if I'm correct
Taking ratios
Let the shadow length=x ft
[tex]\\ \sf\longmapsto 40:60=6:x[/tex]
[tex]\\ \sf\longmapsto \dfrac{40}{60}=\dfrac{6}{x}[/tex]
[tex]\\ \sf\longmapsto \dfrac{4}{6}=\dfrac{6}{x}[/tex]
[tex]\\ \sf\longmapsto 4x=6(6)[/tex]
[tex]\\ \sf\longmapsto 4x=36[/tex]
[tex]\\ \sf\longmapsto x=\dfrac{36}{4}[/tex]
[tex]\\ \sf\longmapsto x=9[/tex]
The graph shows the solution of the following system of equations. y=-5/3x+3 y=1/3x-3 What is the solution? A. (-3,2) B. (3,2) C. (-3,-2) D. (3,-2)
Answer:
(3,-2)
Step-by-step explanation:
-5/3x + 3 = 1/3x - 3
-5/3x = 1/3x - 6
-2x = -6
x = 3
y = -5/3(3) + 3
y = -5 + 3
y = -2
Can someone help me with this?
Answer:
183.3 in^3
Step-by-step explanation:
Find the volume of the rectangular bottom
V = l*w*h
V = 5*5*6 =150 in^3
Find the volume of the triangular pyramid
V = 1/3 Bh where B is the area of the base and h is the height
V = 1/3 ( 5*5) * 4 = 100/3
Add the two volumes together
150 + 100/3
150 +33.3
183.3 in^3
A study examines the relationship between being a registered nurse (yes/no) and passing a cultural competency exam (yes/no) among a group of 987 randomly selected employees at your hospital. What test would be appropriate to determine if there is an association
Answer:
The appropriate test to determine if there is an association between being a registered nurse and passing a cultural competency exam among a group of 987 randomly selected hospital employees is a:
Chi-square Test.
Step-by-step explanation:
The Chi-Square Test uses either a diagram (like a scatter plot) or a hypothesis test to show the existence of an association between two variables or statistically demonstrate that a relationship exists between the two variables. Using the computed t-score, the significant association between two categorical variables can be measured and established.
8x-5/6x
Find all real numbers for which the rational expression is undefined
9514 1404 393
Answer:
as written: noneperhaps intended: 0Step-by-step explanation:
The expression written here is interpreted according to the Order of Operations as ...
8x -(5/6)x
This reduces to (7 1/6)x, which is defined for all real numbers.
__
Maybe you intended the expression ...
(8x -5)/(6x)
This expression is undefined where its denominator is zero, at x = 0.
A company that produces DVD drives has a 12% defective rate. Let X represent the number of defectives in a random sample of 55 of their drives.
Required:
a. What is the probability the sample will contain exactly 8 defective drives?
b. What is the probability the sample will contain more than 8 defective drives?
c. What is the probability the sample will contain less than 8 defective drives?
d. What is the expected number of defective drives in the sample?
Answer:
a) 0.1287 = 12.87% probability the sample will contain exactly 8 defective drives
b) 0.2092 = 20.92% probability the sample will contain more than 8 defective drives.
c) 0.6621 = 66.21% probability the sample will contain less than 8 defective drives.
d) The expected number of defective drives in the sample is 6.6
Step-by-step explanation:
For each DVD, there are only two possible outcomes. Either it is defective, or it is not. The probability of a DVD being defective is independent of any other DVD, which means that the binomial probability distribution is used to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
And p is the probability of X happening.
A company that produces DVD drives has a 12% defective rate.
This means that [tex]p = 0.12[/tex]
Let X represent the number of defectives in a random sample of 55 of their drives.
This means that [tex]n = 55[/tex]
a. What is the probability the sample will contain exactly 8 defective drives?
This is [tex]P(X = 8)[/tex]. So
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 8) = C_{55,8}.(0.12)^{8}.(0.88)^{47} = 0.1287[/tex]
0.1287 = 12.87% probability the sample will contain exactly 8 defective drives.
b. What is the probability the sample will contain more than 8 defective drives?
This is:
[tex]P(X > 8) = 1 - P(X \leq 8)[/tex]
In which:
[tex]P(X \leq 8) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5) + P(X = 6) + P(X = 7) + P(X = 8)[/tex]
Then
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 0) = C_{55,0}.(0.12)^{0}.(0.88)^{55} = 0.0009[/tex]
[tex]P(X = 1) = C_{55,1}.(0.12)^{1}.(0.88)^{54} = 0.0066[/tex]
[tex]P(X = 2) = C_{55,2}.(0.12)^{2}.(0.88)^{53} = 0.0244[/tex]
[tex]P(X = 3) = C_{55,3}.(0.12)^{3}.(0.88)^{52} = 0.0588[/tex]
[tex]P(X = 4) = C_{55,4}.(0.12)^{4}.(0.88)^{51} = 0.1043[/tex]
[tex]P(X = 5) = C_{55,5}.(0.12)^{5}.(0.88)^{50} = 0.1450[/tex]
[tex]P(X = 6) = C_{55,8}.(0.12)^{6}.(0.88)^{49} = 0.1648[/tex]
[tex]P(X = 7) = C_{55,7}.(0.12)^{7}.(0.88)^{48} = 0.1573[/tex]
[tex]P(X = 8) = C_{55,8}.(0.12)^{8}.(0.88)^{47} = 0.1287[/tex]
So
[tex]P(X \leq 8) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5) + P(X = 6) + P(X = 7) + P(X = 8) = 0.0009 + 0.0066 + 0.0244 + 0.0588 + 0.1043 + 0.1450 + 0.1648 + 0.1573 + 0.1287 = 0.7908[/tex]
[tex]P(X > 8) = 1 - P(X \leq 8) = 1 - 0.7908 = 0.2092[/tex]
0.2092 = 20.92% probability the sample will contain more than 8 defective drives.
c. What is the probability the sample will contain less than 8 defective drives?
This is:
[tex]P(X < 8) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5) + P(X = 6) + P(X = 7)[/tex]
With the values we found in b.
[tex]P(X < 8) = 0.0009 + 0.0066 + 0.0244 + 0.0588 + 0.1043 + 0.1450 + 0.1648 + 0.1573 = 0.6621[/tex]
0.6621 = 66.21% probability the sample will contain less than 8 defective drives.
d. What is the expected number of defective drives in the sample?
The expected value of the binomial distribution is:
[tex]E(X) = np[/tex]
In this question:
[tex]E(X) = 55(0.12) = 6.6[/tex]
The expected number of defective drives in the sample is 6.6
PLS HELP! What is the mistake made below in solving x2 – 12x + 10 = 0 using the completing the square method?
x2 – 12x + 10 = 0
x2 – 12x + (- 6)2 = - 10 + (- 6)2
x2 – 12x + 36 = 26
(x – 6)(x – 6) = 26
x – 6 = √26
x = 6 + √26
Answer:
Step-by-step explanation:
Everything is correct. But you forgot to add
x = 6 - square root of 26. The answer is
x = 6 + square root of 26 or
x = 6 - square root of 26
For the function F defined by F(x) = x2 – 2x + 4, find F(b+3).
Answer:
[tex]\displaystyle F(b + 3) = b^2 + 4b + 7[/tex]
Step-by-step explanation:
We are given the function:
[tex]\displaystlye F(x) = x^2 - 2x + 4[/tex]
And we want to find F(b + 3).
We can substitute:
[tex]\displaystyle F(b + 3) = (b + 3)^2 - 2(b+3) + 4[/tex]
Expand:
[tex]\displaystyle = (b^2 + 6b + 9) + (-2b -6) + 4[/tex]
Rearrange:
[tex]\displaystyle = (b^2) + (6b-2b) + (9 - 6 + 4)[/tex]
Combine like terms. Hence:
[tex]\displaystyle = b^2 +4b + 7[/tex]
In conclusion:
[tex]\displaystyle F(b + 3) = b^2 + 4b + 7[/tex]
simplified the expression y(y2 - y + 4)
Answer:
y^3 -y^2 +4y
Step-by-step explanation:
y(y2 - y + 4)
Distribute
y^3 -y^2 +4y
Simplify: [tex]\sqrt{36} - \sqrt{6} + \sqrt{126}[/tex]
what is the answer I need help?
Answer:
8 1/8 units^3
Step-by-step explanation:
This figure is a rectangular prism, and the volume of a rectangular prism is given by the formula:
lwh
But since we have the area of the base snd the height of the figure, there is also one formula that we can use to find the volume:
bh
Which means area of base times the height.
USE THE FORMULA bh:
16 1/4 x 1/2
= 65/4 x 1/2
= 65/8
SIMPLIFIED: 8 1/8
Volume is measured in cubic units
SO YOUR ANSWER IS 8 1/8 units^3
any equations that equal three?
A newsstand spends $600 a month on rent and electricity, and it spends $2
for each magazine that it sells. The newsstand charges $5 for each
magazine. If n is the number of magazines, which equation represents the
profit function of the newsstand?
O A. p = 2n + 600
B. p = 3n-600
O c. p = 600n + 3
O D. p = 5n-600
Answer: B. p = 3n-600
Step-by-step explanation:
Cost = 2n + 600Earned = 5nProfit(p) = Earned - Cost
p = 5n - (2n + 600) = 5n - 2n - 600 = 3n - 600
The equation representing the profit function of the newsstand is
p = 3n - 600
Option B is the correct answer.
What is a function?A function has an input and an output.
A function can be one-to-one or onto one.
It simply indicated the relationships between the input and the output.
Example:
f(x) = 2x + 1
f(1) = 2 + 1 = 3
f(2) = 2 x 2 + 1 = 4 + 1 = 5
The outputs of the functions are 3 and 5
The inputs of the function are 1 and 2.
We have,
The revenue generated by selling n magazines is 5n dollars.
The cost of selling n magazines is the sum of the cost of purchasing n magazines and the fixed cost of rent and electricity, which is $2n + $600.
Now,
The profit function can be represented by:
p = revenue - cost
= 5n - (2n + 600)
= 3n - 600
Thus,
The equation representing the profit function of the newsstand is
p = 3n - 600
Learn more about functions here:
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PLEASE HELP!!!!!!!!!!!!!!!! (answer in decimal!!!!!!!!)
9514 1404 393
Answer:
0.75
Step-by-step explanation:
You know that ...
P(S or T) = P(S) +P(T) -P(S and T)
When events are mutually exclusive, P(S and T) = 0. Then ...
P(S or T) = 5/8 + 1/8 = 6/8 = 3/4
P(S or T) = 0.75
Help!!????
Please!!!????
Answer:
true
mark me brainist if it comes out to be true
Answer:
The answer is TRUE.
Step-by-step explanation:
Draw the line segment with endpoints (-5, 9) and (-1, -7) and find the value of y if x=-4;-2.5;-2;-1.5;0 plz answer asap
Answer:
5, - 1, - 3, - 5, - 11
Step-by-step explanation:
The equation of the line is y=-4x-11. The y values corresponding to x are 5, - 1, - 3, - 5, - 11
in order for the parallelogram to be a rhombus, x=?
[tex]\\ \large\sf\longmapsto x + 15 = 2x - 40 \\ \\ \large\sf\longmapsto x - 2x = - 40 - 15 \\ \\ \large\sf\longmapsto - x = - 55\\ \large\sf\longmapsto x = 55[/tex]
The value of x is 55 degrees.
What is rhombus?A rhombus is a diamond-shaped quadrilateral that has all four sides equal
What are the properties of a rhombus?The properties of a rhombus are:
Opposite angles are equal.All sides are equal and, opposite sides are parallel to each other.Diagonals bisect each other perpendicularly.Sum of any two adjacent angles is 180°According to the given question.
We have a rhombus.
Since, we know that the diagonals of the rhombus bisect the angles.
Therefore,
[tex](x+15)^{o} = (2x-40)^{o}[/tex]
Solve, the above expression for x.
[tex]\implies x +15 = 2x -40\\\implies 15+40 = 2x -x \\\implies 55 = x \\0r\ x = 55^{o}[/tex]
Hence, the value of x is 55 degrees.
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Solve the inequality
Answer:
hope this helps buddy, please mark the brainliest.
Step-by-step explanation:
If f(x)=3x^2-x+6, evaluate f(-4)
Answer:
f(-4) = 58
Step-by-step explanation:
Let x = -4:
[tex]f(-4)=3(-4)^2-(-4)+6\\\\f(-4)=3(16)+4+6\\\\f(-4)=48+4+6\\\\f(-4)=58[/tex]
To mail an envelope first class the us pot charges 0.32 cents for the first ounce and 0.24 cents for each additional ounce. Use an inequality to find the maximum number of whole ounces that can be mailed for $7.98
Answer:
Not sure about the inequality, but maximum ounces is 31 ounces.
Might be.
[tex]7.98 \geqslant .24x + .32[/tex]
PLS PLS PLS HELP QUICKKKK
Find the value of x in each case
Answer:
KI and HE are parallel
So we apply the law of exterior angles ;
3X=X + 180– 2X
3X +X = 180
4X= 180
X= 180/4
X= 45
I hope I helped you^_^
PLZ HELP- I NEED HELP IM A LIL SLOW
Answer:
7 and above
Step-by-step explanation:
Go and 7 draw a dot and a arrow to the right
Answer:
Step-by-step explanation:
what is 88.92 x 21.33
Answer:
By multiplying 88.92 from 21.33 we get 1896.6636.
Hope it's helpfulAnswer:
1896.6636
Step-by-step explanation:
Hope this helps
El valor de "x" que es solución de la ecuación 5x + 22 = 2x + 29 es:
Answer:
x =7/ 3
Step-by-step explanation:
5x+ 22= 2x+ 29
⇔5x - 2x= 29 - 22
⇔3x = 7
⇔x = 7/3
how induction coil work
Answer:
Induction produces an electromagnetic field in a coil to transfer energy to a work piece to be heated. When the electrical current passes along a wire, a magnetic field is produced around that wire
Step-by-step explanation:
a team's stadium has a capacity of 86,047. The fan base is notorious for selling out of tickets every game. If every game sells out this year, how many tickets are sold in their 12 game regular season play?
Answer:
1,032,564 tickets
Step-by-step explanation:
Find how many tickets they sell in total by multiplying the capacity of the stadium by the number of games in the season:
86,047(12)
= 1,032,564
So, if every game sells out, 1,032,564 tickets will be sold.
Which expression is not a polynomial
Answer:
the last option [tex]x^{3}[/tex] + 1 / x
Step-by-step explanation:
first option's x has the power 3
second option's x has the power 1
third option's x has the power 1
but in the last option it has the power -1
polynomials doesn't support negative power
*remember
PLEASE HELP URGENT!!!
Janine determines that the total resistance in her circuit is 80 ohms. Using the inverse equation modeling this situation, find the resistance of the second lightbulb.
The resistance of the second lightbulb is ohms.
A. 120
B. 240
C. 300
D. 40
The sum of resistors arranged in parallel is the inverse of the sum of the inverses of the magnitudes of the individual resistances
The correct option for the resistance of the second light bulb in ohms (Ω) is option B;
B. 240
The reason why option B is the correct answer is s follows:
Known parameters:
Based on a online search, the question appears to have some parts missing which can be as follows;
The resistance of the first light bulb = 120 Ω
Janine's model of the total resistance of the circuit, [tex]t = \mathbf {\dfrac{120 \cdot r }{r + 120} }[/tex]
Where;
r = The resistance of the second light bulb
The unknown parameter:
Resistance of the second light bulb
Method:
Find r using Janine's model of the total resistance, which is the equation of total resistances in parallel arrangement
The inverse relationship modelling the sum, t, of resistances, r, and 120, arranged in parallel, presented as follows;
[tex]\mathbf {\dfrac{1}{t} } =\dfrac{1}{120} + \dfrac{1}{r}[/tex]
∴ [tex]\mathbf {\dfrac{1}{t}} = \dfrac{r + 120 }{120 \cdot r}[/tex]
Therefore, by finding the inverse of both sides of the above equation, we get Janine's model as follows;
[tex]t = \mathbf {\dfrac{120 \cdot r }{r + 120} }[/tex]
The above equation is the inverse equation modelling the total resistance of the parallel arrangement of the resistances in the lightbulb
The question details include:
The total resistance in her circuit, t = 80 Ω
Solution:
Plugging in t = 80 in [tex]t = \mathbf {\dfrac{120 \cdot r }{r + 120} }[/tex], gives;
[tex]80 = \mathbf {\dfrac{120 \cdot r }{r + 120} }[/tex]
Therefore, we get;
80·(r + 120) = 120·r
80·r + 80 × 120 = 120·r
∴ 120·r - 80·r = 80 × 120 = 9,600
120·r - 80·r = 40·r
∴ 40·r = 9,600
r = 9,600/40 = 240
The resistance of the second light bulb, r = 240 Ω
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Answer:240
Step-by-step explanation:
i watched the walk through
