Find quotient ..........

If a student randomly guesses at 20 multiple-choice questions, find the probability that the student gets exactly four correct.

ad-work [718]

Answer:

Probability = 0.190

Step-by-step explanation:

Given:

Number of questions, 'n' = 20

Each question has four choices.

Let event of choosing correct answer be success and its probability be represented by 'p'.

Therefore, event of choosing wrong answer is failure and its probability be represented by 'q'.

Now, probability of success is choosing one correct answer out of 4 options. So, $p=\frac{1}{4}=0.25$

Now, 'p' and 'q' are complements of each other. Therefore,

$q=1-p=1-0.25=0.75$

Now, we need 4 successes. Therefore, $x=4$

Using Bernoulli's theorem to find 'x' successes from 'n' questions, we get:

$P(x)=_{x}^{n}\textrm{C}p^xq^{n-x}$

Plug in 4 for 'x', 20 for 'n', 0.25 for 'p' and 0.75 for 'q'. Solve.

$P(4)=_{4}^{20}\textrm{C}(0.25)^4(0.75)^{20-4}\\P(4)=_{4}^{20}\textrm{C}(0.25)^4(0.75)^{16}\\P(4)=4845\times (0.25)^4\times (0.65)^{16}\\\\P(4)=0.1896\approx0.190$

Therefore, the probability of getting 4 correct answers out of 20 questions is 0.190.

6 0

3 years ago

What is 35 percent of 70

11111nata11111 [884]

35 Percent of 70 is 24.5
We assume, that the number 70 is 100% - because it's the output value of the task. We assume, that x is the value we are looking for. If 70 is 100%, so we can write it down as 70=100%. We know, that x is 35% of the output value, so we can write it down as x=35%. <span>Now we have two simple equations: 1.)70=100% 2.)x=35%</span>where left sides of both of them have the same units, and both right sides have the same units, so we can do something like that: 70/x=100%/35% Now we just have to solve the simple equation, and we will get the solution we are looking for.

3 0

3 years ago

Read 2 more answers

Which expression is equivalent to 5(2+7)?

frosja888 [35]

Answer:

I can help you but first I need the rest of the answers to find out what's it equivalent to.

4 0

3 years ago

Makers Corp. had additions to retained earnings for the year just ended of $205000. The firm paid out $185000 in cash divends, a

forsale [732]

Answer:

3.9

Step-by-step explanation:

The retained earnings for the year is $205,000

The firm paid out $185,000 in cash dividend

It has total equity of$4.90 million

100,000 common shares are outstanding

Therefore the earnings per share van be calculated as follows

= 205,000+185,000/100,000

= 390,000/100,000

= 3.9

Hence the earnings per share is $3.9

6 0

3 years ago

A 2.905x10 B 2.905x10 C 2.95x10

Dafna1 [17]

Answer:

a. 29.05 b. 29.05 c. 29.5

6 0

2 years ago