For each die, there are only two possible outcomes, either a 3 or a 4 is rolled, or it is not. The result of a roll is independent of any other roll, hence, the <em>binomial distribution</em> is used to solve this question.

Binomial probability distribution

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

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

The parameters are:

x is the number of successes.

n is the number of trials.

p is the probability of a success on a single trial.

In this problem:

There are 9 rolls, hence $n = 9$ .

Of the six sides, 2 are 3 or 4, hence $p = \frac{2}{6} = 0.3333$

The desired probability is:

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

In which:

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

Then

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

$P(X = 0) = C_{9,0}.(0.3333)^{0}.(0.6667)^{9} = 0.026$

$P(X = 1) = C_{9,1}.(0.3333)^{1}.(0.6667)^{8} = 0.117$

Then:

$P(X < 2) = P(X = 0) + P(X = 1) = 0.026 + 0.117 = 0.143$

$P(X \geq 2) = 1 - P(X < 2) = 1 - 0.143 = 0.857$

0.857 = 85.7% probability that at least 2 of the rolls come up as a 3 or a 4.

For more on the binomial distribution, you can check brainly.com/question/24863377

7 0

2 years ago

Show what i% 18 out of 25

boyakko [2]

i 18
---- = ----
100 25

25i 1800
----- = -------
25 25

i = 72

72%

6 0

3 years ago

Question 4 pleaseeeeeee

arsen [322]

Answer:

Step-by-step explanation:

Unit rate means one quantity in terms of another unit quantity. In the answer choices, we see that the denominator is always in terms of UNIT LITERS (1 L), so that means, we have to find gallons in terms of UNIT LITERS.

It means, we have to divide gallons by liters to get in terms of unitary liters.

Let's check the first line:

19.5/75 = 0.26 Gallons / 1 Liter

Now, checking 2nd:

39/150 = 0.26 Gallons / 1 Liter

So, yes, they are the same and other 2 lines would be the same as well. The unit rate is:

0.26 gal/1L

That's answer choice B

7 0

3 years ago