In Spring 1990, John enrolls in 9, 12, 15 or 18 credit hours with probabilities 0.1, 0.3, 0.4 and 0.2 respectively. What is the probability that John enrolls in at least 15 hours? What is the mean number of credit hours enrolled for John? What is the standard deviation for the variable 'number of hours enrolled' for John?
Contingency Table
A contingency table can be defined as the visual representation of the relationship between two or more categorical variables that can be evaluated and registered. It is a categorical version of the scatterplot, which is used to investigate the linear relationship between two variables. A contingency table is indeed a type of frequency distribution table that displays two variables at the same time.
Binomial Distribution
Binomial is an algebraic expression of the sum or the difference of two terms. Before knowing about binomial distribution, we must know about the binomial theorem.
In Spring 1990, John enrolls in 9, 12, 15 or 18 credit hours with probabilities 0.1, 0.3, 0.4 and 0.2 respectively.
What is the
What is the
What is the standard deviation for the variable 'number of hours enrolled' for John?
Solution:
Let X be the number of hours enrolled for John.
From the given information, the probability distribution of X is
Then, the probability that John enrolls in at least 15 hours is
Thus, the probability that John enrolls in at least 15 hours is 0.6.
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