Assalamu’Alaykum,

- The calculator Casio fx-991MS having too many facilities that can aid students in hard times. For the particular instance, the regression mode.
- Many a times in many syllabus Statistics is included which is very scoring and easy but the problem is it consumes a lot of time and if not proceeded cautiously a single mistake makes the entire solution wrong.

Consider the example of the following data table.

here we’re asked to compute mean, variance, standard deviation, cov(x,y), and co-efficient of co-variance ‘r’.

x1 3 5 7 9 11 13 17 19 23 y2 4 6 8 10 17 51 62 7 15

The conventional method that is used by the students all across is to draw a table and then calculate various values like

And for the current example a table as follows is made

and then the values under the headings are calculated as per the formula. Then all the values are added.

### All of this makes it too much of a heavy task.

## - Short-Cut

Using the calculator the desired quantity can be calculated within one or two steps

Follow the procedure as follows

Follow the procedure as follows

- : Turn on the calculator
- : Get into the regression mode by pressing 2
- : Select the linear mode by pressing 1
- : Congratulations! You’re now in the regression mode
- : Feed the values of x and y by pressing the values and separating them ',' (comma) and then press the M+ button to save the value in the calculator.
- Save all the values using the above steps, and when you're done press AC button.
- Now to calculate the mean of x press “ Shift” then press “2” and then press “1”.
- Now to calculate the mean of y press “ Shift” then press “2” then press “right navigation” and then press “1”.
- Now to calculate variance of x press “ Shift” then press “2” and then press “2”.
- Now to calculate variance of x press “ Shift” then press “2” then press “right navigation” and then press “2”.
- Now to calculate the co-relation coefficient ‘r’ press “ Shift” then press “2” then press “right navigation” then press “right navigation” and then press “3”.

**Thus saving a lot of time and labour with optimum accuracy….**

**A video demonstrating the above steps in detail will be posted in some days… **