Find the exact value of tan A in simplest radical form. PLEASE HELP

According to an airline, flights on a certain route are on time 80 % of the time. suppose 10 flights are randomly selected and

natulia [17]

(a) This is a binomial experiment since there are only two possible results for each data point: a flight is either on time (p = 80% = 0.8) or late (q = 1 - p = 1 - 0.8 = 0.2).
(b) Using the formula:
P(r out of n) = (nCr)(p^r)(q^(n-r)), where n = 10 flights, r = the number of flights that arrive on time:
P(7/10) = (10C7)(0.8)^7 (0.2)^(10 - 7) = 0.2013
Therefore, there is a 0.2013 chance that exactly 7 of 10 flights will arrive on time.
(c) Fewer than 7 flights are on time means that we must add up the probabilities for P(0/10) up to P(6/10).
Following the same formula (this can be done using a summation on a calculator, or using Excel, to make things faster):
P(0/10) + P(1/10) + ... + P(6/10) = 0.1209
This means that there is a 0.1209 chance that less than 7 flights will be on time.
(d) The probability that at least 7 flights are on time is the exact opposite of part (c), where less than 7 flights are on time. So instead of calculating each formula from scratch, we can simply subtract the answer in part (c) from 1.
1 - 0.1209 = 0.8791.
So there is a 0.8791 chance that at least 7 flights arrive on time.
(e) For this, we must add up P(5/10) + P(6/10) + P(7/10), which gives us
0.0264 + 0.0881 + 0.2013 = 0.3158, so the probability that between 5 to 7 flights arrive on time is 0.3158.

6 0

3 years ago

(a) Find a vector parallel to the line of intersection of the planes −4x+2y−z=1 and 3x−2y+2z=1.

valentinak56 [21]

Find the intersection of the two planes. Do this by solving for z in terms of x and y ; then solve for y in terms of x ; then again for z but only in terms of x.

-4x + 2y - z = 1 ==> z = -4x + 2y - 1

3x - 2y + 2z = 1 ==> z = (1 - 3x + 2y)/2

==> -4x + 2y - 1 = (1 - 3x + 2y)/2

==> -8x + 4y - 2 = 1 - 3x + 2y

==> -5x + 2y = 3

==> y = (3 + 5x)/2

==> z = -4x + 2 (3 + 5x)/2 - 1 = x + 2

So if we take x = t, the line of intersection is parameterized by

r(t) = ⟨t, (3 + 5t )/2, 2 + t⟩

Just to not have to work with fractions, scale this by a factor of 2, so that

r(t) = ⟨2t, 3 + 5t, 4 + 2t⟩

(a) The tangent vector to r(t) is parallel to this line, so you can use

v = dr/dt = d/dt ⟨2t, 3 + 5t, 4 + 2t⟩ = ⟨2, 5, 2⟩

or any scalar multiple of this.

(b) (-1, -1, 1) indeed lies in both planes. Plug in x = -1, y = 1, and z = 1 to both plane equations to see this for yourself. We already found the parameterization for the intersection,

r(t) = ⟨2t, 3 + 5t, 4 + 2t⟩

3 0

3 years ago

The defect length of a corrosion defect in a pressurized steel pipe is normally distributed with mean value 30 mm and standard d

skelet666 [1.2K]

Answer:

$z=-0.842$

And if we solve for a we got

$a=30 -0.842*7.8=23.432$

So the value of height that separates the bottom 20% of data from the top 80% is 23.432.

Step-by-step explanation:

Let X the random variable that represent the heights of a population, and for this case we know the distribution for X is given by:

$X \sim N(30,7.8)$

Where $\mu=30$ and $\sigma=7.8$

For this part we want to find a value a, such that we satisfy this condition:

$P(X>a)=0.80$ (a)

$P(X$ (b)

As we can see on the figure attached the z value that satisfy the condition with 0.20 of the area on the left and 0.80 of the area on the right it's z=-0.842

If we use condition (b) from previous we have this:

$P(X$

$P(z$

But we know which value of z satisfy the previous equation so then we can do this:

$z=-0.842$

And if we solve for a we got

$a=30 -0.842*7.8=23.432$

So the value of height that separates the bottom 20% of data from the top 80% is 23.432.

8 0

3 years ago

PLEASE HELP

Neko [114]

Answer:

55.5 square feet

Step-by-step explanation:

so the dog house consists of 4 walls, two roof sections, and two triangle bits to make the roof pointy (I'm sure they have a name but I don't know what it is lol) Of the walls there would be 2 of the longer walls and 2 of the shorther ones. Knowing this we just have to add together the area of each part to find the total surface area.

So starting with the walls:

two of them are 4 feet by 2 feet.

The area of a rectangle is just length x width

so those two would have an area of 8 ft^2

and the other two are 3 feet by 2 feet so they would have an area of 6 ft^2

the roof sections are also rectangles with dimensions of 4 feet by 2.5 feet

4x2.5=10 so each side of the roof has a surface area of 10 ft^2

now the triangle parts have a base of 3 feet and a height of 2.5 feet

the formula for area of a triangle is base x height / 2

3x2.5=7.5

7.5/2= 3.75

now we add them together

8+8+6+6+10+10+3.75+3.75=55.5

so the total surface area is 55.5 square ft

8 0

3 years ago

Solve for N 2/9n= −6

artcher [175]

Answer:

n=-27

Step-by-step explanation:

Step-By-Step on how to solve it is in the image shown below.

Hope this helps! :)

3 0

3 years ago