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adelina 88 [10]

2 years ago

11

El valor de las variables

1 answer:

Leno4ka [110]2 years ago

8 0

Answer:

<em>25 / 2</em>

Step-by-step explanation:

Find ( D × $\frac{E}{F}$ ) if D = 5, E = 10, F = 4

5 × $\frac{10}{4}$ = <em>25 / 2</em>

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Find each complex conjugate of 9i

gregori [183]

Answer:

-9i

Step-by-step explanation:

the complex conjugate of a+bi is a-bi

0+9i is 0-9i

7 0

2 years ago

Plss help i dont understand

Crazy boy [7]

Here’s the picture.

Equation: 48=4x-12

Answer: x=15

5 0

2 years ago

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Movies Plus charges its customers a $10 monthly service fee plus $2 for each movie the customer rents. Movies For Less charges $

Natasha_Volkova [10]

Answer: A) movies for less cost $5 more

Step-by-step explanation:

10 × 3 =30

15 × 2= 30+10=40 movie plus

15 × 3= 45 movies for less

8 0

3 years ago

Read 2 more answers

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

Deon bought a desktop computer and a laptop computer. Before finance charges, the laptop cost $250 less than the desktop. He pai

zysi [14]

Answer:

300

Step-by-step explanation:

Let x = cost of desktop computer; then x - 250 = cost of laptop computer

converting % to decimals, 9% = 0.09 and 6% = 0.06

Then, 0.09x + (x - 250)0.06 = $300

0.09x + 0.06x - 15 = $300

0.15x = $315

x = $2100

then x - 250 = $1850

Proof: $2100•0.09 + 1850•0.06 = $189 + $111 = $300

7 0

3 years ago