Question

An expert in oil economics, has decided to check a series of hypotheses about the behavior of the WTI price and make estimates about the future price of oil. For this reason, he took the average WTI prices for the last 28 years, which are given below in order to calculate the general average price. In addition, the expert wants to calculate the breakage price where 50% of them have been higher and lower, and which is the price that has been presented more frequently in said period.

25 20 15 15 17 14 18 22 19 16 19 19 18 19

17 14 19 21 23 25 27 38 76 103 77 80 88 87

Answer 1

Data:

25
20
15
15
17
14
18
22
19
16
19
19
18
19
17
14
19
21
23
25
27
38
76
103
77
80
88
87

Mean	33.96429
Median	19.5
Mode	19

Average WTI prices for the last 28 years = Mean = 33.96429

Breakage price where 50% of them have been higher and lower = Median = 19.5

The price that has been presented more frequently in said period = Mode = 19

Mean = Average = Sum of all observations / Total number of observations = Sum/28 = 951 / 28 = 33.96429

Median Calculation :

Arrange the data in ascending or descending order first.

Median is the value which exactly separates the data in two equal halves i.e 50% of the data is higher than median value and 50% of data is lower than the median value.

14

14

15

15

16

17

17

18

18

19

19

19

19

19

20

21

22

23

25

25

27

38

76

77

80

87

88

103

Since there are even number of observations i.e 28 ( 28 is even number ).

Median = Average of 14th and 15th observation ( after arranging in ascending or descending order )

Median = (19 +20 ) / 2 = 19.5

A mode is the most repeated observation or the observation which occurs the most.

"19" occurs the most i.e 5 times.

Therefore, Mode = 19