If the standard deviation of a random variable is 5,what is its variance?
. Any normal distribution is
continuous
discrete
.
some are discrete, some are continuous
a binomial distribution
.
is Poisson distribution
. Let X be a binomial random variable with number of trials 100 and expected value 20. What is the probability of success of X?
. There are 17 blue, 5 green, and 3 red balls in a jar. We randomly select a ball and return it back to the jar. We repeat it 8 times. To find the probability of the event that every time we get a green ball we need to use the following distribution:
binomial with number of trials 8 and probability of success 0.2
binomial with number of trials 25 and probability of success 0.5
binomial with number of trials 5 and probability of success 0.2
binomial with number of trials 8 and probability of success 0.8
binomial with number of trials 8 and probability of success 1/3
Poisson Distribution with average 5
Poisson Distribution with average 8
binomial with number of trials 25 and probability of success 0.2
. The average number of homes with 3 or more bedrooms sold by Acme Reality is 14 homes per week. To find the probability that exactly 3 such homes will be sold tomorrow we need to use the following distribution:
Poisson distribution with mean 2
Poisson distribution with mean 14
Poisson distribution with mean 7
Poisson distribution with mean 3
Binomial with number of trials 7 and probability of success 2/7
Binomial with number of trials 2 and probability of success 2/7
Binomial with number of trials 7 and probability of success 1/7
Standard normal distribution
. A random variable X assumes values 1,2,3,…, 8,9,and 10, each with the same probability, namely the probability 0.1. Find the probability of X getting at least 3.
. A random variable X assumes values 1,2,3,…, 8,9,10, each with the same probability, namely the probability 0.1. Find the probability of X getting no more than 4.
10. A card is drawn, with replacement, from a regular deck of cards 16 times. Let random variable X represent number of clubs among those 16 cards selected (there are 13 clubs in every deck; there are 52 cards in a deck). Find the variance of X,
. The length of life of an instrument produced by a machine has a normal distribution with a mean of 12 months and standard deviation of 2 months. Find the probability that an instrument produced by this machine will last less than 7 months.Round to the nearest thousandth.
. The length of life of an instrument produced by a machine has a normal distribution with a mean of 12 months and standard deviation of 2 months.Find the probability that an instrument produced by this machine will last between 7 and 12 months. Round to the nearest thousandth
