strontium-90 is a radioactive material that decays according to the function A(t)=A0e−0.0244t, where A0 is the initial amount present and A is the amount present at time t​ (in years). Assume that a scientist has a sample of 400 grams of​ strontium-90. ​
(a) What is the decay rate of​ strontium-90?
​(b) How much​ strontium-90 is left after 30 ​years?
​(c) When will only 100 grams of​ strontium-90 be​ left?
​(d) What is the​ half-life of​ strontium-90?

​(a) The decay rate of​ strontium-90 is nothing​%.
​(Type an integer or a decimal. Include the negative sign for the decay​ rate.)

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.

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.

Answer:

y^3 -y^2 +4y

Step-by-step explanation:

y(y2 - y + 4)

Distribute

y^3 -y^2 +4y

9514 1404 393

Answer:

Step-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.

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

Answer:

x =7/ 3

Step-by-step explanation:

5x+  22=  2x+  29

⇔5x - 2x= 29 - 22

⇔3x = 7

⇔x = 7/3

Answer:

hope this helps buddy, please mark the brainliest.

Step-by-step explanation:

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

[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.

A rhombus is a diamond-shaped quadrilateral that has all four sides equal

The properties of a rhombus are:

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.

Find out more information about rhombus here:

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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

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]

Answer:

By multiplying 88.92 from 21.33 we get 1896.6636.

Answer:

1896.6636

Step-by-step explanation:

Hope this helps

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.

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.

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

Answer:

true

mark me brainist if it comes out to be true

Answer:

The answer is TRUE.

Step-by-step explanation:

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:

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

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]

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

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:

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

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]

Answer:

Not sure about the inequality, but maximum ounces is 31 ounces.

Might be.

[tex]7.98 \geqslant .24x + .32[/tex]

Answer: B. p = 3n-600

Step-by-step explanation:

Profit(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.

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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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

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

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^_^