data.mat file contains raw ECG data with the $360$ Hz sampling rate.

$1)$ Plot the first $15$s of raw ECG data.

You must use the filters for implementation of following steps.

$2)$ Plot heartrate $($in bpm$)$ as a function of time.

$3)$ Number of QRS complexes between $30$min and $35$min $($print on command window$).$

in MATLAB