Plzz help and no wrong answer need to be done asap

According to the National Bridge Inspection Standard (NBIS), public bridges over 20 feet in length must be inspected and rated e

slamgirl [31]

Answer:

1.80% probability that in a random sample of 12 major Denver bridges, at least 4 will have an inspection rating of 4 or below in 2020.

Step-by-step explanation:

For each bridge, there are only two possible outcomes. Either it has rating of 4 or below, or it does not. The probability of a bridge being rated 4 or below is independent from other bridges. So we use the binomial probability distribution to solve this problem.

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.

For the year 2020, the engineers forecast that 9% of all major Denver bridges will have ratings of 4 or below.

This means that $p = 0.09$

Use the forecast to find the probability that in a random sample of 12 major Denver bridges, at least 4 will have an inspection rating of 4 or below in 2020.

Either less than 4 have a rating of 4 or below, or at least 4 does. The sum of the probabilities of these events is 1.

So

$P(X < 4) + P(X \geq 4) = 1$

We want $P(X \geq 4)$

So

$P(X \geq 4) = 1 - P(X < 4)$

In which

$P(X < 4) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3)$

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

$P(X = 0) = C_{12,0}.(0.09)^{0}.(0.91)^{12} = 0.3225$

$P(X = 1) = C_{12,1}.(0.09)^{1}.(0.91)^{11} = 0.3827$

$P(X = 2) = C_{12,2}.(0.09)^{2}.(0.91)^{10} = 0.2082$

$P(X = 3) = C_{12,3}.(0.09)^{3}.(0.91)^{9} = 0.0686$

$P(X < 4) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) = 0.3225 + 0.3827 + 0.2082 + 0.0686 = 0.982$

Finally

$P(X \geq 4) = 1 - P(X < 4) = 1 - 0.982 = 0.0180$

1.80% probability that in a random sample of 12 major Denver bridges, at least 4 will have an inspection rating of 4 or below in 2020.

6 0

3 years ago

Translate the sentence into an equation. Twice the difference of a number and 6 is 2.

mojhsa [17]

Answer:

let the number be x.

2(x-6)=2

hope it helps

<h2>stay safe healthy and happy....</h2>

7 0

3 years ago

Sunflower growth 1 week it grew 2 and va half inches in two weeks it grew 2 and 3 fourth in 3 weeks it grew 3 and one fourth how

Liula [17]

Answer:

The Growth of sunflower duing 3 weeks is 8.5 inches or 8 (1/2).

Step-by-step explanation:

Given:

Growth of sunflower each week .

To find :

Total growth during 3 weeks?

Solution:

According to given data:

Growth is

1st week=2 and 1/2 inches=5/2=2.5 inches .
2nd week =2 and 3/4 inches=11/4 inches.
3rd week=3 and 1/4 inches=13/4 inches.

Total growth is given by,

=growth of (1st week +2 week+ 3 week)

=5/2+11/4+13/4

=34/4

=17/2

=8 and 1/2 inches.

Hence the overall growth is about 17/2 or 8.5 inches in 3 weeks .

6 0

3 years ago

This year the CDC reported that 30% of adults received their flu shot. Of those adults who received their flu shot,

Vlad [161]

Using conditional probability, it is found that there is a 0.1165 = 11.65% probability that a person with the flu is a person who received a flu shot.

Conditional Probability

$P(B|A) = \frac{P(A \cap B)}{P(A)}$

In which

P(B|A) is the probability of event B happening, given that A happened.

$P(A \cap B)$ is the probability of both A and B happening.

P(A) is the probability of A happening.

In this problem:

Event A: Person has the flu.

Event B: Person got the flu shot.

The percentages associated with getting the flu are:

20% of 30%(got the shot).

65% of 70%(did not get the shot).

Hence:

$P(A) = 0.2(0.3) + 0.65(0.7) = 0.515$

The probability of both having the flu and getting the shot is:

$P(A \cap B) = 0.2(0.3) = 0.06$

Hence, the conditional probability is:

$P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.06}{0.515} = 0.1165$

0.1165 = 11.65% probability that a person with the flu is a person who received a flu shot.

To learn more about conditional probability, you can take a look at brainly.com/question/14398287

7 0

2 years ago

Explain answer !! <br><br> ( WILL GIVE BRAINLEST)

Ganezh [65]

Answer:find the solution to the system of equations below.start by adding the equation

{-2x+2y=-8

{2x+y=5

Step-by-step explanation:The given system of equation are:

1---- y= x -4

2----- y=4 x+2

Equation (1) - Equation (2)

→0= x -4 - (4 x+2)

→0= -3 x -6-----[Adding and subtracting like terms]

Adding 3 x on both sides

→3 x= -6

Dividing by 3 on both sides

→x = -2

→Substituting the value of x in equation 1, we get

y= -2 -4

y =-6

→Solution set =(x,y)=(-2, -6)

Don't used the graph to find the solution.

4 0

3 years ago