9x +y=-5 Coefficient of x

"the life length x (in years) of a dvd player" is exponentially distributed with mean 5 years. what is the probability that a mo

loris [4]

The exponential distribution is:
$\lambda e^{- \lambda x}$
where $\lambda = \frac{1}{mean}=\frac{1}{5}$

The probability we want is how likely will a dvd player last more than 8 years, given it has already lasted 5 years
To find this, you use conditional probability.
$P(A|B) = \frac{P(A and B)}{P(B)}$
where A is P(x>8) and B is P(x>5)
To find these probabilities, integrate over the distribution:
$P(x \ \textgreater \ N) = \int_N^{\infty} \frac{1}{5} e^{-x/5} dx = e^{-N/5}$

Sub into conditional probability formula:

$P(x \ \textgreater \ 8 | x\ \textgreater \ 5) = \frac{P(x\ \textgreater \ 8)}{P(x\ \textgreater \ 5)} = \frac{e^{-8/5}}{e^{-5/5}} = e^{-3/5} = 0.549$

Final Answer: Given a dvd player is more than 5 years old, the probability that it will last another 3 more years is about 54.9%

3 0

3 years ago

Which scenario is best represented by the equation y = 8x?

harkovskaia [24]

Answer:

The answer is A.

Step-by-step explanation:

6 0

3 years ago

A certain library assesses fines for overdue books as follows. on the first day that a book is overdue, the total fine is $0.10.

Volgvan

It the fourt day the total is 0.70 because
Day one: .10
Day two: you double it so .20
Day three: you double it again so .40
Day four: you add .30 so .70 is the total

3 0

3 years ago

The length of a rectangle is 12 in. and the perimeter is 56 in. find the width of the rectangle

pentagon [3]

The perimeter p of the rectangle with length l and width w is:
p = 2l + 2w
that is, two times its length and two times its width, lets solve for the width w and substitute known data:
p = 2l + 2w
2w = p - 2l
w = (p - 2l)/2
w = (56 - (2*12))/2
w = (56 - 24)/2
w = 32/2
w = 16
therefore the width of the rectangle is 16 in

8 0

3 years ago

(Crys) Im in 11 grade and in applied geometry I need help crys and how do you show

Snowcat [4.5K]

Answer:

1. -2/3 3. -5/4 5. 3/2 FOR THE REST OF THE PARTS LOOK THROUGH THE EXPLANATIONS

Step-by-step explanation:

Before I start the workings, I'll give a little explanation on this topic.

So, the equation of a straight line is

y = mx + c

where x and y are any coordinates of any point on the line.

m is the gradient or slope

m can be calculated using 2 formulas,

formula 1: Rise/Run

where rise is the how much a graph goes upwards or downwards, if its upwards use positive integer and if its downwards use negative integer.

Run is how much a graph moves to the right or to the left, if it moves to the right is is positive, if it moves to the left it is negative.

Formula 2: (y2-y1)/(x2-x1)

the values of these are taken through any 2 coordinates on the line.

and c is the y-intercept(the point where the line crosses the y-axis.

MOVING TO ANSWERING NOW

1. Dotted points on the line are (1,0) and (4,-2)

Formula of slope,

U can use any of the 2 formulas given above

I'll show both for this question

m = (y2-y1)/(x2-x1) = (-2-0)/(4-1) = -2/3

OR

m = rise/run = where rise is -2 and run is 3 so -2/3

2. TRY DOING THIS ONE YOURSELF

For the next part I'll do 3 and 5 for your understanding, try doing 2 and 4 on your own to understand.

3. Coordinates given (13,1) and (1,16)

m = (y2-y1)/(x2-x1) = (16-1)/(1-13) = 15/-12 simplify this and it becomes -5/4

5. (-8,-14) and (-10,-17)

m = (y2-y1)/(x2-x1) = (-17-(-14))/(-10-(-8)) = -3/-2 = 3/2

FOR THE NEXT PART I'LL DO 7,8 AND 10 FOR YOU, TRY DOING 9 ON YOUR OWN FOR PRACTICE.

I WILL ALSO ATTACH FILES FOR THE NEXT PARTS IN ORDER OF QUESTIONS SO SEE THEM.

7. y = x + 3 this means y = 1x +3 which means:

1 is the gradient

3 is the y-intercept

so 1 as a fraction is 1/1 which means rise is one upwards and run is 1 to the right.

Now go to the graph on the y-axis and plot the point 3, (0,3) is your y-intercept. From their rise by one and run by one this will lead u to point (1,4)

Mark both these points and make a line through them.

8. x = -5

now look at this equation in the form of y = mx + c

0 = 1x + 5 the means y is 0 and it is already told in the question that x = -5

if u rearrange 0 = 1x + 5 it will give you x = -5

now when y is 0 x = -5 put a point on the coordinate (-5,0) and draw a vertical straight line.

10. y = (1/4)x - 1

slope is 1/4 which means rise is 1 and run is 4

y-intercept is -1

now go to y=-1 which is the coordinate (0,-1) and rise by one and run by 4, this will take u to the coordinate (4,0) now put a dot on both coordinates, connect them and put a line through them.

3 0

1 year ago