55% of 19.6 is what number?

Let the number of chocolate chips in a certain type of cookie have a Poisson distribution. We want the probability that a cookie

ludmilkaskok [199]

Answer:

$\lambda \geq 6.63835$

Step-by-step explanation:

The Poisson Distribution is "a discrete probability distribution that expresses the probability of a given number of events occurring in a fixed interval of time or space if these events occur with a known constant mean rate and independently of the time since the last event".

Let X the random variable that represent the number of chocolate chips in a certain type of cookie. We know that $X \sim Poisson(\lambda)$

The probability mass function for the random variable is given by:

$f(x)=\frac{e^{-\lambda} \lambda^x}{x!} , x=0,1,2,3,4,...$

And f(x)=0 for other case.

For this distribution the expected value is the same parameter $\lambda$

$E(X)=\mu =\lambda$

On this case we are interested on the probability of having at least two chocolate chips, and using the complement rule we have this:

$P(X\geq 2)=1-P(X$

Using the pmf we can find the individual probabilities like this:

$P(X=0)=\frac{e^{-\lambda} \lambda^0}{0!}=e^{-\lambda}$

$P(X=1)=\frac{e^{-\lambda} \lambda^1}{1!}=\lambda e^{-\lambda}$

And replacing we have this:

$P(X\geq 2)=1-[P(X=0)+P(X=1)]=1-[e^{-\lambda} +\lambda e^{-\lambda}[]$

$P(X\geq 2)=1-e^{-\lambda}(1+\lambda)$

And we want this probability that at least of 99%, so we can set upt the following inequality:

$P(X\geq 2)=1-e^{-\lambda}(1+\lambda)\geq 0.99$

And now we can solve for $\lambda$

$0.01 \geq e^{-\lambda}(1+\lambda)$

Applying natural log on both sides we have:

$ln(0.01) \geq ln(e^{-\lambda}+ln(1+\lambda)$

$ln(0.01) \geq -\lambda+ln(1+\lambda)$

$\lambda-ln(1+\lambda)+ln(0.01) \geq 0$

Thats a no linear equation but if we use a numerical method like the Newthon raphson Method or the Jacobi method we find a good point of estimate for the solution.

Using the Newthon Raphson method, we apply this formula:

$x_{n+1}=x_n -\frac{f(x_n)}{f'(x_n)}$

Where :

$f(x_n)=\lambda -ln(1+\lambda)+ln(0.01)$

$f'(x_n)=1-\frac{1}{1+\lambda}$

Iterating as shown on the figure attached we find a final solution given by:

$\lambda \geq 6.63835$

4 0

2 years ago

Shawn earns $12.75 per hour. How many hours does she need to work to earn $102 or more. Write and solve an inequality.

astra-53 [7]

First we divide 102 by 12.75 to get the hours which is 8 hours. So it would take 8 hours

4 0

2 years ago

Write a system of equations to describe the situation below, solve using substitution, and fill in the blanks. Two students in t

melomori [17]

Answer:

The system of equation used to find the Total number of flash cards made are $\left \{ {{5x+5} \atop {6x}} \right.$ .

In 5 minutes, each student will have 30 flash cards.

Step-by-step explanation:

Given:

Number of flash cards already made by Tristan = 5

Number of flash card Tristan makes in 1 min = 5

Number of flash card Josh makes in 1 min = 6

We need to find the How long will Josh have same number of flashcards.

Also We need to find how many flashcards will each student have at that point.

Solution:

Let the number of minutes be $'x'$ .

Now we can say that;

Total number of flash cards made by Tristan is equal to Number of flash cards already made by Tristan plus Number of flash card Tristan makes in 1 min multiplied by number of minutes.

framing in equation form we get;

Total number of flash cards made by Tristan = $5+5x$