In: Statistics and Probability
Suppose the data shown here are the results of a survey to investigate gas prices. Ten service stations were randomly selected in each city and the figures represent the prices of a litre of unleaded regular gas. What can we tell about the relative price of gas in the two cities?
City 1:
1.029 |
1.02 |
1.017 |
1.002 |
0.996 |
1.017 |
1.014 |
1.014 |
1.014 |
0.983 |
City 2:
0.999 |
1.026 |
1.017 |
1.008 |
0.99 |
1.038 |
1.017 |
1.032 |
1.011 |
1.014 |
Design a test to determine if there is a difference in mean gas prices in the two cities use alpha = .01
By simply looking at the prices nothing can be inferred so we
test for difference of means.
To test for the difference of means we need to first calculate the
sample mean and variance of the two samples provided.
Mean and standard deviation for city 2:
Therefore the mean prices of gas of the two cities are not
different.