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3 years ago

A bag contains two red marbles, two green ones, one lavender one, two yellows, and two orange marbles. HINT [See Example 7.]

Mathematics

1 answer:

hichkok12 [17]3 years ago

7 0

2 sets of 4 marbles because there’s eight in all so 8 divided by 4 is 2

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5.2.14. For the negative binomial pdf p (k; p, r) = k+r−1 (1 − p)kpr, find the maximum likelihood k estimator for p if r is know

Volgvan

Answer:

$\hat p = \frac{r}{\bar x +r}$

Step-by-step explanation:

A negative binomial random variable "is the number X of repeated trials to produce r successes in a negative binomial experiment. The probability distribution of a negative binomial random variable is called a negative binomial distribution, this distribution is known as the Pascal distribution".

And the probability mass function is given by:

$P(X=x) = (x+r-1 C k)p^r (1-p)^{x}$

Where r represent the number successes after the k failures and p is the probability of a success on any given trial.

Solution to the problem

For this case the likehoof function is given by:

$L(\theta , x_i) = \prod_{i=1}^n f(\theta ,x_i)$

If we replace the mass function we got:

$L(p, x_i) = \prod_{i=1}^n (x_i +r-1 C k) p^r (1-p)^{x_i}$

When we take the derivate of the likehood function we got:

$l(p,x_i) = \sum_{i=1}^n [log (x_i +r-1 C k) + r log(p) + x_i log(1-p)]$

And in order to estimate the likehood estimator for p we need to take the derivate from the last expression and we got:

$\frac{dl(p,x_i)}{dp} = \sum_{i=1}^n \frac{r}{p} -\frac{x_i}{1-p}$

And we can separete the sum and we got:

$\frac{dl(p,x_i)}{dp} = \sum_{i=1}^n \frac{r}{p} -\sum_{i=1}^n \frac{x_i}{1-p}$

Now we need to find the critical point setting equal to zero this derivate and we got:

$\frac{dl(p,x_i)}{dp} = \sum_{i=1}^n \frac{r}{p} -\sum_{i=1}^n \frac{x_i}{1-p}=0$

$\sum_{i=1}^n \frac{r}{p} =\sum_{i=1}^n \frac{x_i}{1-p}$

For the left and right part of the expression we just have this using the properties for a sum and taking in count that p is a fixed value:

$\frac{nr}{p}= \frac{\sum_{i=1}^n x_i}{1-p}$

Now we need to solve the value of $\hat p$ from the last equation like this:

$nr(1-p) = p \sum_{i=1}^n x_i$

$nr -nrp =p \sum_{i=1}^n x_i$

$p \sum_{i=1}^n x_i +nrp = nr$

$p[\sum_{i=1}^n x_i +nr]= nr$

And if we solve for $\hat p$ we got:

$\hat p = \frac{nr}{\sum_{i=1}^n x_i +nr}$

And if we divide numerator and denominator by n we got:

$\hat p = \frac{r}{\bar x +r}$

Since $\bar x = \frac{\sum_{i=1}^n x_i}{n}$

4 0

3 years ago

The height H of a skydiver t seconds after jumping. Let T be the independent variable, and assume the skydiver jumps from a heig

Rina8888 [55]

Answer:

25 seconds

Step-by-step explanation:

Skydiving.

height (in feet) above the earth=h(t)= -16t^2 + 10,000

the time it would take to fall when h is 0

-16t^2 + 10,000=0

-16t^2=-10000

16t^2=10000

t^2=10000/16=625

t=sqrt 625=25 seconds

6 0

3 years ago

Which Statement about 4(x-3) is True?

Sophie [7]

Answer: it’s b because if you times that by anything it will always be a product I think

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers

Triangle FGH is an equilateral triangle.FH=6x+1,FG=3x+10,and GH=9x-8

Lena [83]

Answer:

Acute triangle

x = 3

GH = 19

Step-by-step explanation:

7 0

3 years ago

Need help with a couple of geometry word problems. Giving 100 points, tysm if you help :)

dlinn [17]

Answer:

Hope it helps

Step-by-step explanation:

1: B

2: B

3: D

4: C

5: A

6 0

3 years ago