What is the sum of 2/7 + 2/5 ?<br> please help 10 points and brainlest

Use the fact that the mean of a geometric distribution is μ= 1 p and the variance is σ2= q p2. A daily number lottery chooses th

butalik [34]

Answer:

a). The mean = 1000

The variance = 999,000

The standard deviation = 999.4999

b). 1000 times , loss

Step-by-step explanation:

The mean of geometric distribution is given as , $\mu = \frac{1}{p}$

And the variance is given by, $\sigma ^2=\frac{q}{p^2}$

Given : $p=\frac{1}{1000}$

= 0.001

The formulae of mean and variance are :

$\mu = \frac{1}{p}$

$\sigma ^2=\frac{q}{p^2}$

$\sigma ^2=\frac{1-p}{p^2}$

a). Mean = $\mu = \frac{1}{p}$

= $\mu = \frac{1}{0.001}$

= 1000

Variance = $\sigma ^2=\frac{1-p}{p^2}$

= $\sigma ^2=\frac{1-0.001}{0.001^2}$

= 999,000

The standard deviation is determined by the root of the variance.

$\sigma = \sqrt{\sigma^2}$

= $\sqrt{999,000}$ = 999.4999

b). We expect to have play lottery 1000 times to win, because the mean in part (a) is 1000.

When we win the profit is 500 - 1 = 499

When we lose, the profit is -1

Expected value of the mean μ is the summation of a product of each of the possibility x with the probability P(x).

$\mu=\Sigma\ x\ P(x)= 499 \times 0.001+(-1) \times (1-0.001)$

= $ 0.50

Since the answer is negative, we are expected to make a loss.

4 0

2 years ago

The function below is written in vertex form or intercept form. Rewrite them in standard form and show your work.

lora16 [44]

Answer:

The standard form as $y=5x^2+30x+41$

Step-by-step explanation:

Given: A function which is written in vertex form or intercept form.

We have to re-write it in standard form that in terms of

Given $y = 5(x+3)^2-4$

Squaring using $(a+b)^2=a^2+b^2+2ab$ , we get,

$y=5(x^2+9+6x)-4$

Multiply 5 inside , we get,

$y=5x^2+45+30x-4$

Solving further , we get,

$y=5x^2+30x+41$

Thus , we have obtained the standard form as $y=5x^2+30x+41$

8 0

2 years ago

Read 2 more answers

If the exterior angle of a regular polygon is 15 degree, find the central angle ?

Ugo [173]

Answer: 360/15=24 sides

Step-by-step explanation:

6 0

2 years ago

5x + 10y = 18

SOVA2 [1]

5x + 10y = 18

x = y -6, we substitute this into first equation.

5x + 10y = 18

5*(y - 6) + 10y = 18

5y - 30 + 10y = 18

So it the last option from the top.

4 0

3 years ago

Read 2 more answers

1.17375 rounded to nearest tenth

Elden [556K]

Answer:

1.2

Step-by-step explanation:

Since we are rounding it by the tenth, it means we are rounding to the 1st digit to the right of the decimal.

We know 7 is greater then 5 meaning we round up

.1 + .1 is equal to .2 meaning its 1.2

If you still don't understand, I recommend you talk to your teacher

5 0

2 years ago

Read 2 more answers

What is the sum of 2/7 + 2/5 ? please help 10 points and brainlest