probability help

  1. N

    probability density

    Hi All I am currently doing Master in data science. I came across the function PDF probability density function which is used to find cumulative probability(range) of a continuous random variable. The PDF probability density function is plotted against probability density in y axis...
  2. I

    Probability Question!

    The probability that a person in the United States has dark brown eye color is 18%. Three unrelated people in the United States are selected at random. a) What is the probability that all three have dark brown eye colour ? b) What is the probability that at least one person has dark brown eye...
  3. C

    Redundancy probability in employment

    The idea of being made redundant after working so many years in a company is everyone's nightmare. I am currently working in a company employing 145 people (excluding management) where the management recently announced that 45 people out of the 145 will be made redundant in the very near...
  4. B

    Conditional probability of an event given two independent events

    I am dealing with an interesting probability problem. I had 16 subjects randomly divided into 4 different rooms, each room having 4 seats. The subjects were given a question to solve. We knew from our prior experience that only 50% people could solve the problem. In our study, 7 of the 16 people...
  5. F

    Committee Combination

    Hi. I have used the below formulation of the problem. Kindly let me know whether I am correct or wrong. Q. "A condominium management committee has 11 members and wishes to divide into three committees with everyone serving on at least one committee, and no one serving on more than one...
  6. F

    Finding Minimum Probability

    Hi. Below is the question in my homework. I don't know whether I've to solve this using Bayes' theorem or I have to provide a general answer. "A mine pit has collapsed and 20 miners are stuck in an elevator under the mine pit. Since they are in the same elevator, assume we know that they...
  7. J

    Probability that X restaurants will be visited if Y people choose independently

    I am trying to determine for Y people selecting from X restaurants (with an equal probability) what the expected value of the number of restaurants chosen would be. All decisions are independent. Ex: 2 people and 2 restaurants - E(X) = 1(.5) + 2(.5) = 1.5 restaurants will be visited on...
  8. B

    Simple probability in R

    Hello, newbie here. I have just started with R and am having trouble with how to enter a seemingly very simple probability question in R. The question is: There is a big court case, and 20% of the adult population believe the accused is innocent prior to jury selection. Assume that the 12...
  9. C

    Probability and coincidences help

    Can someone please help in the breakdown of how I do this question I am completely lost and I am not sure how to even word the answers 3. Suppose studies have shown that approximately 20% (.2) of Americans regularly engage in exercise (at least 3 times per week). a. If one American is...
  10. I

    New YouTube Channel for Stats Help

    Hello Everyone, As a long-time TA in Statistics, I have recently launched a YouTube Channel with the idea of providing help for students who are taking courses in introductory statistics and probability. The videos it contains are the online equivalents of the TA Review Sessions that I offer...
  11. C

    Apartment vacancy question

    My friend is in this exact situation and we are having trouble figuring out the probability - please help! She is looking for a top-floor apartment in a building with 48 units. There are 6 floors and 8 units per floor. 2 units are currently vacant. What is the probability there is a vacant...
  12. L

    Conditional Probability Help.

    Helloooo Statisticians! I have a question that I believe I can solve but somehow I'm not getting the correct answer. So I'd really appreciate if anyone can point out my mistake for me. The question is: The grades of 1st year students were analysed. 70% of the top one quarter of the 1st year...
  13. K

    Finding probability with given mean and standard deviation

    Hi, I have tried to do this using the z value method but I'm not even sure if I'm right. The question is: "The recommended total blood cholesterol for a lower risk of heart disease is less than 200mg/dL. The total blood cholesterol for males aged 20 -29 is normally distributed with a mean of...
  14. T

    Need help calculating some values to be used in a cost/risk analysis

    Hello, **If this is in the wrong forum, could someone tell me where it needs to be before removing it?**** I am needing some help calculating the possible profits I can make for producing certain amounts of 2 different products each month. (Modifying a basic jon boat and reselling it). The...
  15. B

    An interesting probability calculation problem

    Hello all! I'll be really glad if you respond to this question. I am working with an interesting probability calculation problem. In my problem there are ratings for 32 chess players. They are divided into two groups to form two chess teams in such a way that each team contains all types of...
  16. A

    Probability Brain Teaser

    You have 6 pairs of socks - 2 white, 2 black, 2 green You need a matching pair in either white or black - but the lights are out, so you have to choose the socks at random How many socks must you pick before you can know for sure that you have one matching pair either in white or black?
  17. K

    Please help with probability question!

    A game consists of tossing two coins, first a dime and then a nickel. For each coin which comes up a head you win the value of the coin. For each coin which comes up a tail you get nothing. {HH,HT,TH,TT} - each outcome with probability .25 - winnings are 15,10,5,0 a) Find the mean or expected...
  18. Soccer23

    Binomial Probabilities

    Please help me with these two math problems! Please help me with these statistics problems! I'm really new to this online program for school and it's really hard without a teacher or peers to ask for help! :( Approximately 2% of the nation's children (about 1.7 million) have a parent who is...
  19. C

    need help on permutations

    I am trying to solve a problem that can be represented by rolling an n-sided die r times. I need to be able to figure out the probabilities of the size of the set of results. Sorry I can't explain it better. for example, 5 normal dice are rolled. There can be anywhere from 1 to 5 numbers in the...
  20. L

    Probability of a team making the finals

    Hi, I am trying to find how to calculate the probability of "x" number of events happening within "y" opportunities. However each opportunity has a different probability. For example to calculate the probability of "TEAM WOW" winning 0, 1, 2, 3, or 4 games out of the 4 games they play...