Solve for c in the proportion.<br> 6/c = 48/40 c= ?

(1 point) A pond contains 100 fish, of which 40 are carp. If 20 fish are caught from the lake, what are the mean and variance of

marta [7]

Answer:

E(X) = 6

Var(X) = 3.394

Step-by-step explanation:

Let X represent the number of carp caught out of the 20 fishes caught. Now, if we are to assume that each

of the (100, 20) ways to catch the 20 fishes will be equally likely.

Thus, we can say that X fulfills a hypergeometric

distribution with parameters as follows;

n = 20, N = 100, k = 30

Formula for expected mean value in hypergeometric distribution is;

E(X) = nk/N

E(X) = (20 × 30)/100

E(X) = 6

Formula for variance is;

Var(X) = (nk/N) × [((n - 1)(k - 1)/(N-1))) + (1 - nk/N)]

Var(X) = ((20 × 30)/100) × [((20 - 1)(30 - 1)/(100 - 1)) + (1 - (20 × 30/100)]

Var(X) = 6 × 0.5657

Var(X) = 3.394

5 0

2 years ago

A 748-N man stands in the middle of a frozen pond of radius 4.0 m. He is unable to get to the other side because of a lack of fr

Ber [7]

Answer:

The man will take 64 seconds to reach to the south shore of the frozen pond.

Step-by-step explanation:

Given:

Weight of the man = 748 N Mass of the man, $(m)= \frac{W}{g}$ = $\frac{748}{9.8}$ = $76.32$ kg

Radius of the pond $(r)$ = 4 m

Mass of the textbook = 1.2 kg

Velocity at which the textbook is thrown = 4 ms^1

We have to find the velocity of the man after the throw.

Let the velocity is $V_m$ .

Now using law of conservation of momentum we can find the $V_m$ value.

$m_(_b_)V_b_(_i_) +m_(_m_)V_m_(_i_) =m_(_b_)V_b_(_f_)+m_(_m_) V_m_(_f_)$

Considering $V_m_(_f_)=V_m$

And initial velocity of both the man and book i.e $V_b_(_i_)=0,\ V_m_(i_)=0$

So,

⇒ $0 =m_(_b_)V_b_(_f_)+m_(_m_) V_m$

⇒ Plugging the values.

⇒ $V_m=-\frac{m_(_b_)V_b_(_f_)}{m_(_m_)}$

⇒ $V_m=-\frac{1.2\times 4}{76.32}$

⇒ $V_m=-0.062$ ms^-1

Here the negative velocity is meant for opposite direction of the throw.

Numerically we will write, $V_m = 0.062$

With this velocity the man will move towards south.

We have to calculate the time taken by the man to move to its south shore.

And we know $velocity(v)\times time(t) = distance(d)$

Let the time taken be $t$ and $v\times t = d$ and $d=r$ then, $V_m\times t=r$

Then

⇒ $t=\frac{radius\ (r)}{V_m}$

⇒ Plugging the values.

⇒ $t=\frac{4}{0.062}$

⇒ $t =64$ sec

The man will take 64 seconds to reach to the south shore of the frozen pond (circular).

5 0

3 years ago

How do i solve y=20x+500

Vesnalui [34]

<span>Simplifying y = 20x + 500 Reorder the terms: y = 500 + 20x Solving y = 500 + 20x Solving for variable 'y'. Move all terms containing y to the left, all other terms to the right. Simplifying y = 500 + 20x</span>

8 0

3 years ago

A multiple choice exam has 20 questions. Each question has 3 possible answers; there is no partial credit. Only 1 answer out of

amid [387]

Answer:To find out the theoretical probability of the case given, we need to make certain assumptions.

First, we'll assume that he'll attempt all of the questions, i.e he'll attempt all 10 questions.

Next assumption is that each option in each question is equally likely to be marked by the student.

This pretty much leads us to a binomial probability distribution.

Conditions are:

Answers 10 questions.

Each question has 4 options with only one correct answer and all other incorrect answers.

Student is equally likely to pick any outcome in any given question.

Hence, probability of choosing correct answer is 1/4 = 0.25. Probability of choosing incorrect answer is 1–1/4 = 3/4 = 0.75.

The number of trials is 10.

Total number of success is exactly 8 and failure is 2 amongst the 10 questions in any particular order.

Now, calculation is fairly simple.

Binomial probability distribution is such that…

P(8 correct ; 2 wrong)

= 10C8 × (0.25)^8 × (0.75)²

= 405/1048576 ≈ 3.862380981 × 10^-4 ≈ 0.000386

Step-by-step explanation:

6 0

3 years ago

Use the relationship between the angles in the figure to answer the question.

Andrej [43]

X + 52 = 180 b is the answer

4 0

3 years ago

Read 2 more answers

Solve for c in the proportion. 6/c = 48/40 c= ?