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 probability of at least one head?

If you throw a single fair coin multiple times, the probability of getting NO head is:For 1 throw: 1/2

For 2 throws: 1/2 squared = 1/4

For 3 throws: 1/2 cubed = 1/8

etc.

The probability of getting AT LEAST ONE head is the complement; for example, for 3 throws, it would be 1 minus 1/8.

What does probability measures?

From a scale of 1 to 0 probability measure an event will happen, maybe it will happen or it will not happen.

What is the probability that the spinner and number cube both land on 2?

That would depend on how many numbers are on the spinner and the cube. The more numbers there are, the less likely it is that they would both land an any given number.

What is the probability of observing a sample mean of 18 or more from a sample size of 35?

Without knowing the data which is being sampled, it is impossible to answer this other than by saying that the probability is between 0 and 1 inclusive.

Consider a company. If you sample the annual pay of the employees, any mean will be greater than 18 as everyone will be taking home more than £18 per year, so the probability is 1.

Consider a school. If you sample the lengths of feet of the pupils, any mean will be less than 18 as all the feet are less than 18 inches long, so the probability is 0.

If an event has a probability of 1 then it is?

Then it is a certainty that the event is 100% to happen.

When you roll a 6 sided die with faces numbered 1 through 6 and toss a coin what is the probability of rolling a 5 and getting tails?

As the two events are independent multiply the respective probabilities together:

pr(5) = 1/6

pr(tails) = 1/2*

→ pr(5 and tails) = 1/6 × 1/2 = 1/12

*Actually it is slightly less than 1/2 as there is a very small probability that the coin will end up on its edge; for a small coin it is so small that it can be ignored, but with a scaled up coin it becomes a real possibility as (accidentally) demonstrated in the 1997 Royal Institution Christmas Lecture "The Magical Maze"

What is the probability that he gets a number greater than 3 or a prime number if Kevin rolls a 6 sided die?

The possible prime numbers are 2, 3, 5

The possible numbers greater than 3 are 4, 5, 6

→ a success is 2 3, 4, 5, 6

→ pr(prime or > 3) = 5/6

If you flip a coin and roll a 6-sided die what is the probability that you will flip a heads and roll at least a 3?

one in three

1 2 = under 3

3 4 5 6 = at least 3

so 4/6 probability

coin is 1 in 2

4/6 x 1/2 = 4/12 = 1/3

What are the probabilities of spinning red green yellow and blue if a spinner is divided equally into those four colors?

Assuming you want the probability FOR A SINGLE TRY, and you want the numbers in that exact order, the probability for each part (for instance, first = red; or second = green) is 1/4; therefore, the probability for the combination is (1/4) to the power 4.

What will happen if a fair die is rolled 180 times how many times would I expect it to either land on a 3 or a 5?

If you throw the fair die once then the chances are two as there are two numbers to be shown that is 3 or 5.

Total number of faces and numbers in dice = 6.

So, Probability of two numbers falling = 2/6 = 1/3.

If you roll the same die 180 times then chances of landing on either 3 or 5 = 180 x 1/3 = 60.

What is Z-score for x equals 52 when a normal distribution has a mean of 50 and a standard deviation of 20?

You need to ask 1 question at a time, rewording it into 200 characters or less - it helps you to actually think about what is required instead of getting others to do your work for you.

z = (x - µ)/standard deviation

= (52 - 50)/20

= 0.1

(If z is negative it is below the mean.)

What is a example of cluster sampling?

Cluster sampling is a scheme which is used when sampling from the whole population would be too expensive - in terms of time or money. The sample space is divided into clusters, a random sample of clusters is selected and then every member of the population within the selected clusters is studied.

For example, suppose you wanted to collect information from schools across a country and had calculated that a 5% sample was required. Rather than criss-crossing the country, you could divide the country into units: for example counties. You then select counties (your clusters) so that they cover 5% of the nation's schools. Visit each chosen county and sample all schools in it. The selection of counties would probably also need to be controlled so that urban and rural areas are properly represented.

Trending Questions
What is a z-score used for? Why relative frequency maximum probability? A fair die is rolled 9 times compute the probability that a one appears exactly once? What does it mean if you have the same birthday as someone else? Why are the events of spinning a spinner and rolling a number cube independent events? What is the probability of you becoming pregnant in the first month of coming off the pill if you were on it for over five years and your partner uses withdrawal as the current birth control? What does the z score of - 1.3 mean? The two components of distribution are? A test consist of 10 true or false questions 2 pass the test the student must answer atleast 8 correctly if the student guesses on each question what is the probability that the student will pass? Where is probability found? What is contemporary math? What is a sample space diagram? What is the probability of throwing a total of six when you throw a pair of standard dice? Mendel performed his experiment with thousands of pea plants How did this make his probability calculations more reliable? What are the steps of simulating discrete probability diustributions write the general algorithm? What is the probability of picking 20 red marbles out of a bag with 50 marbles where only 20 of them are red and the rest are blue? How do you do probabilty? What is the probability of an adverse event ocurring? What is called area under normal curve? Explain why estimating before you divide 624 by 6 helps you place the first digit in the quotient?