3 30 Points The rain levels in inches for a given mountain r

3. (30 Points): The rain levels in inches for a given mountain region in each quarter over the last three years is given in the below table. Calculate the seasonal index values (15 Points) and predict the rain level for the next year (15 Points).

Years

Seasons

1

2

3

4

1

73

81

76

77

2

89

87

85

92

3

123

115

108

131

4

100

105

100

115

Solution

Season 1

Season 2

Season 3

Season 4

Seasonal index

The total average of the averages = (76.75+88.25+119.25+105)/4

= (389.25)/4

= 97.3125

Seasonal index for first season = ((76.75)/97.3125)*100 =78.8696

Seasonal index for second season = ((88.25)/97.3125)*100 = 90.6872

Seasonal index for third season = ((119.25)/97.3125)*100 = 122.5434

Seasonal index for fourth season = ((105)/97.3125)*100 = 107.8998