On february 15, 2012, students in stt 201 at michigan state university were asked "how old were you on your last birthday? their responses are tallied in the table below: age: 18 19 20 21 22 25frequency: 102 297 95 111 47 48 find the iqr of the age distribution.

3

Step-by-step explanation:

IQR = Median upper range - Median lower range

     =  22 - 19

     =  3

Since the parabola is opening in vertical direction, this shows that the squared term is x.

The sign determines whether the opening is up or down. A negative sign shows a downward opening when the squared term is x.

So, look for the equation with negative coefficient and squared x term. Option A gives such an equation

So, the answer to this question is option A