In: Statistics and Probability
The heating bills for a selected sample of houses in five different cities using various forms of heating are given below (values are in dollars).
City |
Gas Heated Homes |
Central Electric |
Heat Pump |
Ankara |
83 |
90 |
81 |
Konya |
80 |
88 |
83 |
Çorum |
82 |
87 |
80 |
Yozgat |
83 |
82 |
82 |
Kırşehir |
82 |
83 |
79 |
(Note: If “data analysis” OPTION not loaded follow the below instructions to load)
Click àFile (or office button)
Choose à options
Choose à add-ins
Click à go
Mark à Analysis toolpack-VBA
Click à ok
When you click data tab you should see “data analysis” at the upper right corner of the tool bar.
Answer 1.
a. Null Hypothesis, Ho; There is no significant
difference among the average bills of the homes according to the
different heating methods, i.e.
b. Alternative Hypothesis, Ha: There exists at least one
heating method for which the average bill of homes is significantly
different, i.e. there exists at least one
for at least one
c. Between Group Variation = Sum of Squares Between Group = 70
d. F- ratio = 6.7742
e. F-critical = 2.8068
f. Since, F-ratio > F-critical, we Reject Ho at 10%
level of significance and conclude that There exists at least one
heating method for which the average bill of homes is significantly
different, i.e. there exists at least one
for at least one
Answer 2.
a. Null Hypothesis, Ho; There is no significant
difference among the average bills of the homes across different
cities, i.e.
b. Alternative Hypothesis, Ha: There exists at least one
city for which the average bill of homes is significantly
different, i.e. there exists at least one
for at least one
c. Between Group Variation = Sum of Squares Between Group = 19.3333
d. F- ratio = 0.42899
e. F-critical = 2.6053
f. Since, F-ratio < F-critical, we fail to Reject Ho
at 10% level of significance and conclude that There is no
significant difference among the average bills of the homes across
different cities, i.e.
Answer 3.
Answer a. F ratio for the test of equality of bills according to heating methods = Sum of Squares due to Columns = 6.5625
Answer b. F ratio for the test of equality of bills according to cities = Sum of Squares due to Rows = 0.90625