PS_6.2.1 Video lesson - Expected Value and StDev of Random Var

Here is the same table in Desmos.

What do the values in column $$y_1$$ represent?

Desmos will find the sums easily by using the "Total" command, as shown in the image. Or you can type them out individually as shown in the video.

Note: We find the sum of the products (numerator) AND the sum of the probabilities (denominator) to find the mean.

What is the expected value $$E(X)$$ for this binomial distribution?

What's another way of describing the mean for a set of data?

I assigned the variable "m" for the mean (or Expected Value).

Then added the formula (1st option) using the table values and m.

Notice the parenthesis around $$x_1^2\cdot y_1$$ . This ensure you find the sum first and then subtract the mean squared value.

What is the variance for this binomial distribution?

Here I just copied and pasted the variance equation into a square root in Desmos. This allowed me to keep ALL of the decimal place that may be hidden in my final answer of 76.8.

What is the standard deviation of our data set?

What does the standard deviation tell us about our data?

Which calculation is used to find the "Expected Value"?