M represents the slope of a line, changing the slope to positive will make it an incline and changing it to negative will make it a decline. If the slope is a fraction, the smaller the numerator, the steeper the line, the larger the numerator, the less steep the line is.
To write it as a fraction first count the number of decimals and call it (which, in our case, has a value of 3). Multiply the number with to get . Then divide this number by to get from here you can either simplify (if the assignment says so, then the simplified fraction is ) or not.