answersLogoWhite

0

🎒

Probability

The probability of a certain event is a number expressing the likelihood that a specific event will occur, expressed as the ratio of the number of actual occurrences to the number of possible occurrences. In mathematics, it is a measure of how often an event will happen and is the basis of statistics.

14,643 Questions

What is the probabilty of rolling an even number on the number cube and flipping heads on the coin?

A single roll of a fair number cube: 1/2

A single toss of a fair coin: 1/2

Both events: 1/4

How many outcomes if you flip 3 coins?

-- 8 possibilities if the coins are different colors.

-- Only 4 possibilities if you can't tell the coins apart.

What is the probability of throwing dice in the order of 1 2 and 6?

1/120

there are three spots and six numbers on a dice


so 6 numbers on the first spot and 5 numbers on the second spot and 4 in the third spot just multiply them

How many ways are there to arrange the letters in ALABAMA and put four A together?


If the four letters "A" are to be together, "AAAA", then it's like having four different

letters; AAAA, L, B, M.

The number of different arrangements (permutations) of the 7 letters in the word

"ALABAMA" putting the four As together are;

4! =

4x3x2x1 =

24

What is the compound event of flipping a coin and rolling die 3 times?

define success and failure. Heads? or tails. What number or set of numbers do you want on the die? A compound event could be heads for the coin and all 3 die are less than 4.

Is uniform distribution bimodal?

The modes of a probability density function might be defined as the (countable) set of points in the domain of the function for which the function achieves local maxima. Since the probability density function for the uniform distribution is constant by definition it has no local maxima, hence no modes. Hence, it cannot be bimodal.

What is the probability of rolling a dice 7?

With a single throw of a normal die, the probability is 0.

With a single throw of a normal die, the probability is 0.

With a single throw of a normal die, the probability is 0.

With a single throw of a normal die, the probability is 0.

What is the probability of a horse winning the triple crown 2013?

The probability is 0 since it did not happen.

The probability is 0 since it did not happen.

The probability is 0 since it did not happen.

The probability is 0 since it did not happen.

How many such numbers are there in the arrangement h93pkeOr1uwg2mi5bqz6 each of which is immediately preceded by a letter and immediately followed by symbol?

None, since there are no symbols and so nothing which can be "immediately followed by symbol".

None, since there are no symbols and so nothing which can be "immediately followed by symbol".

None, since there are no symbols and so nothing which can be "immediately followed by symbol".

None, since there are no symbols and so nothing which can be "immediately followed by symbol".

What does a probability tree look like?

A tree on its side, with the trunk on the left and an increasing number of branches to the right.

A tree on its side, with the trunk on the left and an increasing number of branches to the right.

A tree on its side, with the trunk on the left and an increasing number of branches to the right.

A tree on its side, with the trunk on the left and an increasing number of branches to the right.

What is the probability of choosing a queen or a king from standard deck of 52 playing cards?

The answer depends on how many cards are drawn, whether or not at random, with or without replacement. The probability for a single card, drawn at random, from a normal deck of playing cards is 2/13.

The answer depends on how many cards are drawn, whether or not at random, with or without replacement. The probability for a single card, drawn at random, from a normal deck of playing cards is 2/13.

The answer depends on how many cards are drawn, whether or not at random, with or without replacement. The probability for a single card, drawn at random, from a normal deck of playing cards is 2/13.

The answer depends on how many cards are drawn, whether or not at random, with or without replacement. The probability for a single card, drawn at random, from a normal deck of playing cards is 2/13.

What is the number of distinct arrangements of the letters of the word ugccsir so that you and i cannot come together?


from itertools import permutations

from string import join


arrangements = [ ]

for p in permutations ( 'ugccsir', 6 ) :

arrangement = join ( p, '' )

if 'ui' in arrangement :

continue

if not arrangement in arrangements :

arrangements . append ( arrangement )


print len ( arrangements )

The above Python code gives a result of 2,220.

What is the probability that 13 rolls of a fair die will show three threes?

Not an easy question. Here's a long but logical answer.

The chance of not getting a 3 on any throw is 5/6, so the chance of not getting any threes in the first 10 throws is (5/6)^10.

Now, having reached that point, the chance of throwing three threes in the last three throws is 1/6 x 1/6 x1/6 or 1/216. So the probability of throwing three threes in any chosen three throws is (5/6)^10 x 1/216. This should seem logical because the probability of throwing three threes in the first three throws followed by ten failures to throw threes, should be the same as just getting threes in the last three throws. The probability is the same for getting threes in only the second, fourth and sixth throw, or any other combination of three throws.

Now, there are a set number of combinations of 13 things taken in groups of three. This is given by the formula for C(13,3) =

(13x12x11x10x9x8x7x6x5x4)/((10x9x8x7x6x5x4x3x2x1)x(3x2x1)). That cancels down to (13x12x11)/(3x2x1), and equals 286.

So, there are this many ways you can pick out three throws which you want to be the threes, and the probability of them actually being threes is the first calculation we did.

The answer to the question is 286 x (5/6)^10 x 1/216 which is 0.2138453, about.

How many possible outcomes are their when you roll five six sided dice?

Here are two ways you can solve this, depending on if order matters or order does not matter:


Order of the dice does matter:

Assuming that you roll a 1, 1, 1, 1, 4 is not the same as rolling a 1, 4, 1, 1, 1


Think of 5 blanks first (one for each six sided dice).[ dice 1 ] [ dice 2 ] [ dice 3 ] [ dice 4 ] [ dice 5 ]


Each dice has 6 sides, so you can have 6 different possibilities per dice. Fill in each blank with how manypossibilities. Then multiply them.


(6) x (6) x (6) x (6) x (6) = 65 = 7776 possibilities.


A few possibilities looks like (I'm not listing all 7776possibilities):

(1, 1, 1, 1, 1), (2, 1, 1, 1, 1), (3, 1, 1, 1, 1), (4, 1, 1, 1, 1), (5, 1, 1, 1, 1), (6, 1, 1, 1, 1), where (1, 1, 1, 1, 1) represents all five dice landing on a 6.


The answer is 7776 possibilities.



Order of the dice does not Matter

Now if 1, 1, 1, 1, 4 is the same as rolling a 1, 4, 1, 1, 1 then the problem is more complex. You can use the following formula (it's a binomial):


C(n+5, 5), where n is the amount of dice

C(5+5,5) = C(10,5)


How to use this:

C(A,B) = A! / [ (A-B)! B! ], where A! is read A factorial


What is a factorial:

n! = n x (n-1) x (n-2) ... x ... (n-n+1)

Example:

5! = 5 x (5-1) x (5-2) x (5-3) x (5-4)

5! = 5 x 4 x 3 x 2 x 1


Plug in your numbers;

C(10,5) = 10! / [ (10-5)! 5! ]

C(10,5) = 10! / ( 5! 5! )


( 1 x 2 x 3 x 4 x 5 x 6 x 7 x 8 x 9 x 10 ) / ( 1 x 1 x 2 x 2 x 3 x 3 x 4 x 4 x 5 x 5 )

= ( 6 x 7 x 8 x 9 x 10 ) / ( 2 x 3 x 4 x 5 ) = 30240 / 120 = 252 possibilities


The equation I gave you works for six sided dice problems. I have verified this answer numerically.


So the answers are:

7776 possibilities if order matters.

252 possibilities if order does not matter

What is the probability of rolling an odd number on 1 roll of die?

With a single die:

There are 6 sides on a dice.

There are 3 sides that are odd (1, 3, 5)

3/6 = 1/2 = 50%


Therefore, a single die has a 50% chance of landing on an odd number.


If you have two dice:

I'll explain this the longer way, however there are short (and simpler explanations) that basically use the fact that a single die is 50%, therefore two independent dice will also be 50%.


Number of dice = 2Sides of a dice = 6


Odd sides: 1, 3, 5, so Number of odd sides on a dice = 3

Even sides: 2, 4, 6, so Number of even sides = 3


Total combinations with two 6 sided dice = (sides on dice x sides on dice) = 6 x 6 = 36


We need to take the fact that:

An odd number + an odd number = even
An even number + an even number = even

An odd number + an even number = odd <--- we want this case


Odd combinations on a dice:

First dice is even, second dice is odd (even sides x odd sides):

(3) x (3) = 9

First dice is odd, second dice is even (odd sides x even sides):

(3) x (3) = 9

Total odd combinations:

9 + 9 = 18


Divide odd combinations by total combinations to get the probability:

18 / 36 = 1/2


You have a 50% chance to roll an odd number on a single roll of two six sided dice.

What does districts must be compact contiguous and substantially equal in population mean?

It means that Gerrymandering is less easy.
Compact: Think of dropping a big spoonful of honey on a table. The result will be a round blob. We would say that the area of contact between the honey and the table is compact. In contrast, if you were to drop a spoonful of water from a couple of inches above the table it would splash out. There would be 'arms' of water that would spread out from the central wet area on the table. The area of contact between the water and the table would not be considered compact.


Contiguous: The city of New York is not contiguous. There's the mainland and there's Long Island, and these pieces are separated by salt water. In contrast the state of Idaho is contiguous--because it's all one big area.


Equal in population: obvious.

What is the probability of drawing a jack and a king?

The probability of drawing a jack and a king in that order from a standard deck is: P(J,K)

=

(4/52)∙(4/51) =

0.006033... ~ 0.006 ~ 0.6%

The probability of drawing a jack and a king in any order is twice the above:

P((J,K)

or (K,J)) =

0.0112066... ~ 0.011

~ 1.1%

Is rolling an even number on a number cube an outcome or an event?

Rolling a dice and getting an even number is an outcome. It is the result of rolling a dice.

What is the probability of drawing an ace or a 8?

(4 + 4) in 52, or 8 in 52, or 2 in 13, or about 0.1538.

What does is mean when the standard deviation is 0?

Intuitively, a standard deviation is a change from the expected value.


For the question you asked, this means that the change in the "results" doesn't exist, which doesn't really happen. If the standard deviation is 0, then it's impossible to perform the test! This shows that it's impossible to compute the probability with the "null" standard deviation from this form:

z = (x - µ)/σ


If σ = 0, then the probability doesn't exist.

What condition must be met to use the normal distribution to approximate the binomial distribution?

A large sample (n > 25) and p, the probability of success on each trial = around 0.5 (0.35 to 0.65).

Independence is already assumed for it to be binomial.

A large sample (n > 25) and p, the probability of success on each trial = around 0.5 (0.35 to 0.65).

Independence is already assumed for it to be binomial.

A large sample (n > 25) and p, the probability of success on each trial = around 0.5 (0.35 to 0.65).

Independence is already assumed for it to be binomial.

A large sample (n > 25) and p, the probability of success on each trial = around 0.5 (0.35 to 0.65).

Independence is already assumed for it to be binomial.

What is the critical z value that corresponds to a confidence level of 88 percent?

z = 1.56 gives a 2-tailed interval for 88%.

z = 1.56 gives a 2-tailed interval for 88%.

z = 1.56 gives a 2-tailed interval for 88%.

z = 1.56 gives a 2-tailed interval for 88%.