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3 years ago

4. The annual salaries of employees in a large company are approximately

Mathematics

1 answer:

svetoff [14.1K]3 years ago

5 0

a. What percent of people earn less than $40000?

Solution: Let S be the random variable of a salary of employee (in $), S ~ N(50000,20000). Then the random

variable X =−50000

20000

~N(0,1).

( < 40000) = ( <

40000 − 50000

20000 ) = ( < −0.5) = (−0.5) = 0.3085375.

Here Φ(x) denotes the cumulative distribution function of a standard normal distribution.

Answer: 31%.

b. What percent of people earn between $45000 and $65000?

Solution:

(45000 < < 65000) = (

45000 − 50000

20000 < <

65000 − 50000

20000 ) = (−0.25 < < 0.75)

= (0.75) − (−0.25) = 0.7733726 − 0.4012937 = 0.3720789.

Answer: 37%.

c. What percent of people earn more than $70000?

Solution:

( > 70000) = ( >

70000 − 50000

20000 ) = ( > 1) = 0.8413447.

Answer: 84%.

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Any one that knows this please help thanks!

nignag [31]

You just need to plug the values: you have to multiply $x$ and $y^2$ , and then divide the result by -3.

So, if $y=2$ , we have $y^2=4$

Which means that $xy^2 = 5\cdot 4 = 20$

And the final answer is $\frac{20}{-3}$

3 0

3 years ago

The projected rate of increase in enrollment at a new branch of the UT-system is estimated by E ′ (t) = 12000(t + 9)−3/2 where E

nexus9112 [7]

Answer:

The projected enrollment is $\lim_{t \to \infty} E(t)=10,000$

Step-by-step explanation:

Consider the provided projected rate.

$E'(t) = 12000(t + 9)^{\frac{-3}{2}}$

Integrate the above function.

$E(t) =\int 12000(t + 9)^{\frac{-3}{2}}dt$

$E(t) =-\frac{24000}{\left(t+9\right)^{\frac{1}{2}}}+c$

The initial enrollment is 2000, that means at t=0 the value of E(t)=2000.

$2000=-\frac{24000}{\left(0+9\right)^{\frac{1}{2}}}+c$

$2000=-\frac{24000}{3}+c$

$2000=-8000+c$

$c=10,000$

Therefore, $E(t) =-\frac{24000}{\left(t+9\right)^{\frac{1}{2}}}+10,000$

Now we need to find $\lim_{t \to \infty} E(t)$

$\lim_{t \to \infty} E(t)=-\frac{24000}{\left(t+9\right)^{\frac{1}{2}}}+10,000$

$\lim_{t \to \infty} E(t)=10,000$

Hence, the projected enrollment is $\lim_{t \to \infty} E(t)=10,000$

8 0

3 years ago

I need help with these questions!! 25 points!!!! That’s what I have

Troyanec [42]

Answer:

7. D

8. A

9. D

10. B

11 A) $640 = 0.8j$

11 B) $\frac{0.8j}{1.15}$

Step-by-step explanation:

Let Emmet work for "m" minutes

Since, Cal worked 4times as this, we can say Cal worked for "4m" minutes

Now, the total time (CAL + EMMET) is 720, so we SUM UP their individual times' expression and equate to 720. Shown below:

4m + m = 720

This is Answer choice D

Let s be the price of each shirt

Each shirt costs "s" each, so 4 shirts cost "4s" in total.

4 shirts costs 60 AFTER 10 dollar discount, so before discount, it was:

60 + 10 = 70 dollars

Hence, 4 shirts cost 70 dollars BEFORE discount, so we can say:

4s = 70

But none of the choices are this, we need to simply manipulate this equation to get our answer (from choices).

How did we get 70? We added 60 and 10. So we can put "60" on the right hand side and "-10" on the left hand side to get:

4s - 10 = 60

This is ultimatley 4s = 70

So the correct answer choice is A

Let Tony's age be "y"

We know grandmother is "3 years MORE than 6 times TONY (y)", thus we can write:

Grandmother is "6y + 3"

Total sum of them both is 87. Thus we can SUM both these expressions and equate to 87. Thus,

y + 6y + 3 = 87

D is the correct choice.

10.

THe total length is "f"

Each piece cut is 3/4

So the number of pieces is the total by each piece, so that is

$\frac{f}{\frac{3}{4}}$

All these "number of pieces" makes 6 shelves (since he used all), so we equate this expression to "6". Now we have:

$\frac{f}{\frac{3}{4}}=6$

That is answer choice B

11 A)

Let Jocelyn's computer's price be "j",

Adrian's is 640, which is 20% LESS THAN Jocelyn's (j), so we can say:

640 is 20% less than "j"

"20% less than j" would be:

j - 0.2j = 0.8j

Now, we can write:

640 = 0.8j

11 B)

We can say:

Adrian is 15% more than Corbin

A = 0.15C + C

A = 1.15C

[note: let adrian's computer price be A and Corbin's computer price be C]

Also we know

0.8j = Adrian

We can put this in to get:

A = 1.15C

C = A/1.15

C = 0.8j/1.15

THis is an expression for Corbin's computer price in terms of j:

$\frac{0.8j}{1.15}$

5 0

3 years ago

Write your answer as an integer or as a decimal rounded to the nearest tenth

Savatey [412]

9514 1404 393

Answer:

8.7

Step-by-step explanation:

We have the side adjacent to the angle and we want the hypotenuse. The relevant trig relation is ...

Cos = Adjacent/Hypotenuse

Solving for the hypotenuse, we find ...

VW = XW/cos(36°) = 7/0.80901

VW ≈ 8.7

4 0

3 years ago

Hey guys can u pls help me.

nadya68 [22]

Answer:

It's b

it's kinda hard to explain but it ends up showing .7x.5 on the example, so your answer is B

4 0

2 years ago

Read 2 more answers