REFLECTION 5
This week I learned about the types of variables namely Discrete and Continuous. Discrete variables are probable outcomes that are countable. Continuous variables on the other hand are data that are on a continuous scale. These variables usually represent measured data like weight, height, and temperature. I also learned about the Discrete Probability Distribution otherwise known as Probability Mass Function or PMF for short. It consists of the values of a random value.
The way to solve for the PMF of Discrete Random Variable is to first get the Value of the random variable X. In this case D represents defective cell phone, and it also represents the random variable X, and N represents the non-defective ones. 3 cell phones are chosen randomly and they will be tested to see if they are defective or not. First we list down all the possible outcomes then we count how many values of X there are in each outcome.
After we count the values of X in each outcome we list down the values in the Number of Defective Cell phones after in this case the values are 0,1, 2, and 3. To get the Probability we count how many times the values appear on the random variable x. 0 appears once and since there are 8 possible outcomes it becomes 1/8. 1 appears three times which makes it 3/8, 2 appears three times as well which makes it 3/8, and 3 appears once which makes it 1/8.
The Probability Histogram is essentially the Histogram of PMF. It uses adjacent rectangles to represent the data.
I also learned about the mean of the random variable and the formula for it is: μ=∑X ⋅ P(X)
or μ= X1 ⋅ P(X1) + X2 ⋅ P (X2) + X3 ⋅ P(X3)+... + Xn ⋅ P(Xn)
X1, X2, X3, ... are the number of X and P(X1,), P(X2), P(X3), ... are the probability of the number of X appearing.