Solution: We are given below data:

Now to find the mean deviation, we use the below formula:

Where:
represents the summation
X, represents the observation.
represents the mean
N represents the number of observation.


Therefore, the mean deviation is:

= 4
Given:
Quadrilateral QRST has diagonals that do NOT bisect each other, are congruent and are not perpendicular.
By checking the options:
Rhombus, rectangle and the square each of them the diagonals bisect each other
So, the answer will be option 4) Isosceles Tra
Morgan should first take the 40% off then apply the $15 coupon
Lets say her total was $150.
If you take the 40% off first, you get $90
150 * .6 = 90 (since you are taking off 40% you are still paying the rest of the 60% so you can just save extra steps by multiplying by .6 and not .4)
Now you subtract 15 from that value.
90 - 15 = 75 If Morgan takes the 40% off first and then applies the $15 dollar coupon, she has to pay $75.
If she applies the $15 coupon first, her total before the 40% is $135
150 - 15 = 135
The total will come out to be $81
$135 * .6 = 81
If Morgan takes the discount first before applying the coupon she has to pay less and saves the most money.