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3 years ago

I don’t understand this

Mathematics

2 answers:

guajiro [1.7K]3 years ago

8 0

Step-by-step explanation:

answer is A, please trust me if I'm right give me brainiest

viktelen [127]3 years ago

6 0

Answer:

Step-by-step explanation:

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An oil drilling company ventures into various locations, and its success or failure is independent from one location to another.

densk [106]

Answer:

a) 18.77% probability that the driller drills at 10 locations and has 1 success

b) 75.60% probability that the driller drills at 10 locations and has at least 2 success

Step-by-step explanation:

For each drill, there are only two possible outcomes. Either it is a success, or it is not. The probability of a drill being a success is independent of other drills. So we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

10 locations

This means that $n = 10$

Suppose the probability of a success at any specific location is 0.25.

This means that $p = 0.25$

(a) What is the probability that the driller drills at 10 locations and has 1 success?

This is P(X = 1).

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 1) = C_{10,1}.(0.25)^{1}.(0.75)^{9} = 0.1877$

18.77% probability that the driller drills at 10 locations and has 1 success

(b) What is the probability that the driller drills at 10 locations and has at least 2 success?

Either there are less than 2 success, or there are at least 2. The sum of the probabilities of these events is decimal 1. So

$P(X < 2) + P(X \geq 2) = 1$

We want $P(X \geq 2)$

$P(X \geq 2) = 1 - P(X < 2)$

In which

$P(X < 2) = P(X = 0) + P(X = 1)$

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 0) = C_{10,0}.(0.25)^{0}.(0.75)^{10} = 0.0563$

$P(X = 1) = C_{10,1}.(0.25)^{1}.(0.75)^{9} = 0.1877$

$P(X < 2) = P(X = 0) + P(X = 1) = 0.0563 + 0.1877 = 0.2440$

$P(X < 2) = P(X = 0) + P(X = 1) = 1 - 0.244 = 0.756$

75.60% probability that the driller drills at 10 locations and has at least 2 success

8 0

3 years ago

The 9th graders are selling tickets to raise

Sidana [21]

Answer:

There were 30 children and 10 adults.

Step-by-step explanation:

Since they sold tickets to adults and childrens, the sum of those tickets must be equal to the total tickets that were sold, so we can mount our first equation as shown below:

adult + children = 40

Each adult ticket costs $9 and each children costs $5 and the total recieved was $240, therefore:

9*adult + 5*children = 240

We can mount the following equation system:

adult + children = 40

9*adult + 5*children = 240

We will multiply the first equation by -5 and sum both equations:

-5*adult -5*children = -200

9*adult + 5*children = 240

4*adult = 40

adult = 40 / 4

adult = 10

adult + children = 40

children = 40 - adult = 40 - 10 = 30

There were 30 children and 10 adults.

3 0

3 years ago

Can someone help me with 3

attashe74 [19]

Area = Length x Width

72 = Length x 6

Length = 12

5 0

3 years ago

Natalie drew a solid that has six faces eight vertices and 12 edges what solid did Natalie draw

Monica [59]

I think Natlie drew a cube :)

5 0

3 years ago

What is the product of 4(8x + 5).

andreyandreev [35.5K]

Answer:

x = 20/32

Step-by-step explanation:

you have to distribute first.

1) times 4 by all the nubmers and figures inside the pharanthesese and so you get 32x + 20

2) you have to solve for x and so you move the 20 to the other side and get 32x = 20

3) you then divided both sides by 32 to get x by itself and you get x = 20/32

8 0

2 years ago

Read 2 more answers