It tells us how far each of the data set in the distribution are far from the mean of the distribution.
The average score of students in Mr. Blake's science class was 73 with a standard deviation of 11, while the average score of students in Mrs. Arnold's class was 75 with a standard deviation of 10.
Since 11>10, Mr Blake's science class is more variable than Mrs. Arnold's class.
The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".
Let X the random variable of interest, on this case we now that:
The probability mass function for the Binomial distribution is given as:
Where (nCx) means combinatory and it's given by this formula:
Part a
Part b
The expected value is givn by:
Part c
For the standard deviation we have this:
Part d
For this case the sample size needs to be higher or equal to 9. Since we need a value such that:
And the dsitribution that satisfy this is
We can verify this using the following code:
"=1-BINOM.DIST(3,9,0.75,TRUE)" and we got 0.99 and the condition is satisfied.