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2 years ago

Sa

Mathematics

1 answer:

max2010maxim [7]2 years ago

8 0

Answer:

12.6% is the percent of change.

Step-by-step explanation:

As Expo Milano 2015 was visited by 22.2 million people.

And it is expected that Expo 2020 Dubai will be visited by 25 million people.

25 - 22.2 = 2.8 million people

so dividing the 2.8 by 22.2 would give us the percentage of increase.

2.8/22.2 = 0.126 which is = 12.6%

Therefore, 12,6% is the percent of change.

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Help! Please !!!<br> <3

MatroZZZ [7]

Move the decimal over 5 times when it's a positive interval notation:

200,000

660,000

4 0

3 years ago

A house increased in value by 36 percent since it was purchased. If thw current value is 306000 what was the value when it was p

LenKa [72]

Answer: 30599.964
Because I did the math

4 0

2 years ago

An article suggests that a poisson process can be used to represent the occurrence of structural loads over time. suppose the me

kirill115 [55]

Answer:

a) $\lambda_1 = 2*2 = 4$

And let X our random variable who represent the "occurrence of structural loads over time" we know that:

$X(2) \sim Poi (4)$

And the expected value is $E(X) = \lambda =4$

So we expect 4 number of loads in the 2 year period.

b) $P(X(2) >6) = 1-P(X(2)\leq 6)= 1-[P(X(2) =0)+P(X(2) =1)+P(X(2) =2)+...+P(X(2) =6)]$

$P(X(2) >6) = 1- [e^{-4}+ \frac{e^{-4}4^1}{1!}+ \frac{e^{-4}4^2}{2!} +\frac{e^{-4}4^3}{3!} +\frac{e^{-4}4^4}{4!}+\frac{e^{-4}4^5}{5!}+\frac{e^{-4}4^6}{6!}]$

And we got: $P(X(2) >6) =1-0.889=0.111$

c) $e^{-2t} \leq 2$

We can apply natural log in both sides and we got:

$-2t \leq ln(0.2)$

If we multiply by -1 both sides of the inequality we have:

$2t \geq -ln(0.2)$

And if we divide both sides by 2 we got:

$t \geq \frac{-ln(0.2)}{2}$

$t \geq 0.8047$

And then we can conclude that the time period with any load would be 0.8047 years.

Step-by-step explanation:

Previous concepts

The exponential distribution is "the probability distribution of the time between events in a Poisson process (a process in which events occur continuously and independently at a constant average rate). It is a particular case of the gamma distribution". The probability density function is given by:

$P(X=x)=\lambda e^{-\lambda x}$

The exponential distribution is "the probability distribution of the time between events in a Poisson process (a process in which events occur continuously and independently at a constant average rate). It is a particular case of the gamma distribution"

Solution to the problem

Let X our random variable who represent the "occurrence of structural loads over time"

For this case we have the value for the mean given $\mu = 0.5$ and we can solve for the parameter $\lambda$ like this:

$\frac{1}{\lambda} = 0.5$

$\lambda =2$

So then $X(t) \sim Poi (\lambda t)$

X follows a Poisson process

Part a

For this case since we are interested in the number of loads in a 2 year period the new rate would be given by:

$\lambda_1 = 2*2 = 4$

And let X our random variable who represent the "occurrence of structural loads over time" we know that:

$X(2) \sim Poi (4)$

And the expected value is $E(X) = \lambda =4$

So we expect 4 number of loads in the 2 year period.

Part b

For this case we want the following probability:

$P(X(2) >6)$

And we can use the complement rule like this

$P(X(2) >6) = 1-P(X(2)\leq 6)= 1-[P(X(2) =0)+P(X(2) =1)+P(X(2) =2)+...+P(X(2) =6)]$

And we can solve this like this using the masss function:

$P(X(2) >6) = 1- [e^{-4}+ \frac{e^{-4}4^1}{1!}+ \frac{e^{-4}4^2}{2!} +\frac{e^{-4}4^3}{3!} +\frac{e^{-4}4^4}{4!}+\frac{e^{-4}4^5}{5!}+\frac{e^{-4}4^6}{6!}]$

And we got: $P(X(2) >6) =1-0.889=0.111$

Part c

For this case we know that the arrival time follows an exponential distribution and let T the random variable:

$T \sim Exp(\lambda=2)$

The probability of no arrival during a period of duration t is given by:

$f(T) = e^{-\lambda t}$

And we want to find a value of t who satisfy this:

$e^{-2t} \leq 2$

We can apply natural log in both sides and we got:

$-2t \leq ln(0.2)$

If we multiply by -1 both sides of the inequality we have:

$2t \geq -ln(0.2)$

And if we divide both sides by 2 we got:

$t \geq \frac{-ln(0.2)}{2}$

$t \geq 0.8047$

And then we can conclude that the time period with any load would be 0.8047 years.

3 0

3 years ago

mr. larsen's third grade class has 22 students, 12 girls and 10 boys. two students must be selected at random to be in the fall

faust18 [17]

The probability that no boys will be chosen is 0.2857

What is probability?

The area of arithmetic called likelihood deals with numerical representations of the chance that an incident can occur or that a press release is true.

Main Body:

Total students =22

total boys = 10

total girls =12

Now we have to chose 2 girls from 12 , so combination is used to select ,

⇒¹²C₂

Also, We have to chose 2 girls from 22 students

so it can be represented as ,

⇒²²C₂

Probability of choosing 2 girls = ¹²C₂/²²C₂

On solving this we will get = 0.2857

Hence the probability is 0.2857

To know more about probability , visit;

brainly.com/question/13604758

#SPJ4

5 0

11 months ago

The first term of a geometric sequence is 6, and the common ratio is 3. What is the 7th term of the sequence?

-BARSIC- [3]

An = a1 r^(n-1)

here a1 = 6 and r = 3 so

a7 = 6 * 3^(7-1)

= 4374 answe

8 0

3 years ago