Answer:
Q3 = 40.5
Step-by-step explanation:
The first step to solve your exercise is ordering all the elements of the data set.
So the ordered data set is:
12, 19, 20, 28, 34, 36, 45, 45
The upper quartile is the median of the upper half of a data set. Mathematically, the upper quartile is the term at the position P defined by the equation below
[tex]P = \frac{3(n+1)}{4}[/tex]
This exercise data-set has a cardinality of 8, so n = 8.
So
[tex]P = \frac{27}{4}[/tex]
However, P = 6.75. When the decimal part is .75, we subtract .25, so P = 6.50.
So, the upper qurtily is the average between the 6th and 7th terms in the ordered set.
Uq = Q3 = (45+36)/2 = 40.5